feat(rust): Display toolchain names (#3414)

This is an actualization of PR #559 as originally envisioned by qryxip.

Adds the ability to display toolchain versions, either as extracted from
environment/settings files or by getting the host triple. As part of
this, several other major changes were needed:
- Many of the smaller functions within the code have been fused, moved,
  or dropped.
- The Rustup environmental info is now initialized lazily using
  OnceCells. This will hopefully lead to a performance increase.
- New configuration variables (`toolchain` and `numver`) have been added
  to allow finer-grained configuration.
- Override information is no longer read from `rustup` output. Instead,
  it is parsed from the same files that rustup would use to determine
  this info.

Co-authored-by: qryxip <qryxip@gmail.com>

Co-authored-by: qryxip <qryxip@gmail.com>

4 files changed, 1147 insertions, 667 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f1e4d383c..5c7d900b1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -33,19 +33,20 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.56"
+version = "1.0.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4361135be9122e0870de935d7c439aef945b9f9ddd4199a553b5270b49c82a27"
+checksum = "08f9b8508dccb7687a1d6c4ce66b2b0ecef467c94667de27d8d7fe1f8d2a9cdc"
 
 [[package]]
 name = "async-broadcast"
-version = "0.3.4"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90622698a1218e0b2fb846c97b5f19a0831f6baddee73d9454156365ccfa473b"
+checksum = "1bbd92a9bd0e9c1298118ecf8a2f825e86b12c3ec9e411573e34aaf3a0c03cdd"
 dependencies = [
  "easy-parallel",
  "event-listener",
  "futures-core",
+ "parking_lot",
 ]
 
 [[package]]
@@ -321,9 +322,9 @@ dependencies = [
 
 [[package]]
 name = "combine"
-version = "4.6.3"
+version = "4.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50b727aacc797f9fc28e355d21f34709ac4fc9adecfe470ad07b8f4464f53062"
+checksum = "2a604e93b79d1808327a6fca85a6f2d69de66461e7620f5a4cbf5fb4d1d7c948"
 dependencies = [
  "bytes",
  "memchr",
@@ -340,9 +341,9 @@ dependencies = [
 
 [[package]]
 name = "const_format"
-version = "0.2.22"
+version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22bc6cd49b0ec407b680c3e380182b6ac63b73991cb7602de350352fc309b614"
+checksum = "0936ffe6d0c8d6a51b3b0a73b2acbe925d786f346cf45bfddc8341d79fb7dc8a"
 dependencies = [
  "const_format_proc_macros",
 ]
@@ -559,9 +560,9 @@ checksum = "453440c271cf5577fd2a40e4942540cb7d0d2f85e27c8d07dd0023c925a67541"
 
 [[package]]
 name = "dyn-clone"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee2626afccd7561a06cf1367e2950c4718ea04565e20fb5029b6c7d8ad09abcf"
+checksum = "21e50f3adc76d6a43f5ed73b698a87d0760ca74617f60f7c3b879003536fdd28"
 
 [[package]]
 name = "easy-parallel"
@@ -577,9 +578,9 @@ checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 
 [[package]]
 name = "enumflags2"
-version = "0.7.4"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b3ab37dc79652c9d85f1f7b6070d77d321d2467f5fe7b00d6b7a86c57b092ae"
+checksum = "e75d4cd21b95383444831539909fbb14b9dc3fdceb2a6f5d36577329a1f55ccb"
 dependencies = [
  "enumflags2_derive",
  "serde",
@@ -597,6 +598,27 @@ dependencies = [
 ]
 
 [[package]]
+name = "errno"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f639046355ee4f37944e44f60642c6f3a7efa3cf6b78c78a0d989a8ce6c396a1"
+dependencies = [
+ "errno-dragonfly",
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "errno-dragonfly"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa68f1b12764fab894d2755d2518754e71b4fd80ecfb822714a1206c2aab39bf"
+dependencies = [
+ "cc",
+ "libc",
+]
+
+[[package]]
 name = "event-listener"
 version = "2.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -660,6 +682,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e9d758e60b45e8d749c89c1b389ad8aee550f86aa12e2b9298b546dda7a82ab1"
 
 [[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+
+[[package]]
 name = "futures-core"
 version = "0.3.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -765,9 +793,9 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.14.2"
+version = "0.14.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3826a6e0e2215d7a41c2bfc7c9244123969273f3476b939a226aac0ab56e9e3c"
+checksum = "5e77a14ffc6ba4ad5188d6cf428894c4fcfda725326b37558f35bb677e712cec"
 dependencies = [
  "bitflags",
  "libc",
@@ -777,6 +805,18 @@ dependencies = [
 ]
 
 [[package]]
+name = "guess_host_triple"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b35a8ce923c7490629d84e12fa2f75e1733f1ec692a47c264f9b7fd632855afc"
+dependencies = [
+ "errno",
+ "libc",
+ "log",
+ "winapi",
+]
+
+[[package]]
 name = "hashbrown"
 version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -784,9 +824,9 @@ checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
 
 [[package]]
 name = "hashbrown"
-version = "0.12.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c21d40587b92fa6a6c6e3c1bdbf87d75511db5672f9c93175574b3a00df1758"
+checksum = "db0d4cf898abf0081f964436dc980e96670a0f36863e4b83aaacdb65c9d7ccc3"
 dependencies = [
  "ahash",
 ]
@@ -822,6 +862,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
 
 [[package]]
+name = "home"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2456aef2e6b6a9784192ae780c0f15bc57df0e918585282325e8c8ac27737654"
+dependencies = [
+ "winapi",
+]
+
+[[package]]
 name = "idna"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -896,15 +945,15 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.121"
+version = "0.2.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "efaa7b300f3b5fe8eb6bf21ce3895e1751d9665086af2d64b42f19701015ff4f"
+checksum = "5916d2ae698f6de9bfb891ad7a8d65c09d232dc58cc4ac433c7da3b2fd84bc2b"
 
 [[package]]
 name = "libgit2-sys"
-version = "0.13.2+1.4.2"
+version = "0.13.3+1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a42de9a51a5c12e00fc0e4ca6bc2ea43582fc6418488e8f615e905d886f258b"
+checksum = "c24d36c3ac9b9996a2418d6bf428cc0bc5d1a814a84303fc60986088c5ed60de"
 dependencies = [
  "cc",
  "libc",
@@ -914,9 +963,9 @@ dependencies = [
 
 [[package]]
 name = "libz-sys"
-version = "1.1.5"
+version = "1.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f35facd4a5673cb5a48822be2be1d4236c1c99cb4113cab7061ac720d5bf859"
+checksum = "92e7e15d7610cce1d9752e137625f14e61a28cd45929b6e12e47b50fe154ee2e"
 dependencies = [
  "cc",
  "libc",
@@ -937,10 +986,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6a104730949fbc4c78e4fa98ed769ca0faa02e9818936b61032d2d77526afa9"
 
 [[package]]
+name = "lock_api"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "327fa5b6a6940e4699ec49a9beae1ea4845c6bab9314e4f84ac68742139d8c53"
+dependencies = [
+ "autocfg",
+ "scopeguard",
+]
+
+[[package]]
 name = "log"
-version = "0.4.16"
+version = "0.4.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6389c490849ff5bc16be905ae24bc913a9c8892e19b2341dbc175e14c341c2b8"
+checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
 dependencies = [
  "cfg-if 1.0.0",
 ]
@@ -990,9 +1049,9 @@ checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
 
 [[package]]
 name = "memchr"
-version = "2.4.1"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
 
 [[package]]
 name = "memmem"
@@ -1119,9 +1178,9 @@ dependencies = [
 
 [[package]]
 name = "num-integer"
-version = "0.1.44"
+version = "0.1.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
 dependencies = [
  "autocfg",
  "num-traits",
@@ -1129,9 +1188,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.14"
+version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
 ]
@@ -1228,7 +1287,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccd746e37177e1711c20dd619a1620f34f5c8b569c53590a72dedd5344d8924a"
 dependencies = [
  "dlv-list",
- "hashbrown 0.12.0",
+ "hashbrown 0.12.1",
 ]
 
 [[package]]
@@ -1265,6 +1324,31 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "427c3892f9e783d91cc128285287e70a59e206ca452770ece88a76f7a3eddd72"
 
 [[package]]
+name = "parking_lot"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d17b78036a60663b797adeaee46f5c9dfebb86948d1255007a1d6be0271ff99"
+dependencies = [
+ "instant",
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d76e8e1493bcac0d2766c42737f34458f1c8c50c0d23bcb24ea953affb273216"
+dependencies = [
+ "cfg-if 1.0.0",
+ "instant",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "winapi",
+]
+
+[[package]]
 name = "path-slash"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1375,9 +1459,9 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.8"
+version = "0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e280fbe77cc62c91527259e9442153f4688736748d24660126286329742b4c6c"
+checksum = "e0a7ae3ac2f1173085d398531c705756c94a4c56843785df85a60c1a0afac116"
 
 [[package]]
 name = "pin-utils"
@@ -1476,9 +1560,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.36"
+version = "1.0.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+checksum = "ec757218438d5fda206afc041538b2f6d889286160d649a86a24d37e1235afd1"
 dependencies = [
  "unicode-xid",
 ]
@@ -1505,15 +1589,28 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "632d02bff7f874a36f33ea8bb416cd484b90cc66c1194b1a1110d067a7013f58"
+checksum = "a1feb54ed693b93a84e14094943b84b7c4eae204c512b7ccb95ab0c66d278ad1"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "rand"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "552840b97013b1a26992c11eac34bdd778e464601a4c2054b5f0bff7c6761293"
+dependencies = [
+ "fuchsia-cprng",
+ "libc",
+ "rand_core 0.3.1",
+ "rdrand",
+ "winapi",
+]
+
+[[package]]
+name = "rand"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
@@ -1559,6 +1656,21 @@ dependencies = [
 
 [[package]]
 name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+dependencies = [
+ "rand_core 0.4.2",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
+
+[[package]]
+name = "rand_core"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
@@ -1618,6 +1730,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+dependencies = [
+ "rand_core 0.3.1",
+]
+
+[[package]]
 name = "redox_syscall"
 version = "0.2.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1778,9 +1899,9 @@ dependencies = [
 
 [[package]]
 name = "serde_repr"
-version = "0.1.7"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "98d0516900518c29efa217c298fa1f4e6c6ffc85ae29fd7f4ee48f176e1a9ed5"
+checksum = "a2ad84e47328a31223de7fed7a4f5087f2d6ddfe586cf3ca25b7a165bc0a5aed"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1893,9 +2014,15 @@ checksum = "7bd3e3206899af3f8b12af284fafc038cc1dc2b41d1b89dd17297221c5d225de"
 
 [[package]]
 name = "slab"
-version = "0.4.5"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9def91fd1e018fe007022791f865d0ccc9b3a0d5001e01aabb8b40e46000afb5"
+checksum = "eb703cfe953bccee95685111adeedb76fabe4e97549a58d16f03ea7b9367bb32"
+
+[[package]]
+name = "smallvec"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2dd574626839106c320a323308629dcb1acfc96e32a8cba364ddc61ac23ee83"
 
 [[package]]
 name = "socket2"
@@ -1921,6 +2048,8 @@ dependencies = [
  "dunce",
  "gethostname",
  "git2",
+ "guess_host_triple",
+ "home",
  "indexmap",
  "local_ipaddress",
  "log",
@@ -2015,9 +2144,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.90"
+version = "1.0.92"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "704df27628939572cd88d33f171cd6f896f4eaca85252c6e0a72d8d8287ee86f"
+checksum = "7ff7c592601f11445996a06f8ad0c27f094a58857c2f89e97974ab9235b92c52"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2035,6 +2164,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "tempdir"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15f2b5fb00ccdf689e0149d1b1b3c03fead81c2b37735d812fa8bddbbf41b6d8"
+dependencies = [
+ "rand 0.4.6",
+ "remove_dir_all",
+]
+
+[[package]]
 name = "tempfile"
 version = "3.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2138,18 +2277,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.30"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "854babe52e4df1653706b98fcfc05843010039b406875930a70e4d9644e5c417"
+checksum = "bd829fe32373d27f76265620b5309d0340cb8550f523c1dda251d6298069069a"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.30"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
+checksum = "0396bc89e626244658bef819e22d0cc459e795a5ebe878e6ec336d1674a8d79a"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2179,9 +2318,9 @@ dependencies = [
 
 [[package]]
 name = "tinyvec"
-version = "1.5.1"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c1c1d5a42b6245520c249549ec267180beaffcc0615401ac8e31853d4b6d8d2"
+checksum = "87cc5ceb3875bb20c2890005a4e226a4651264a5c75edb2421b52861a0a0cb50"
 dependencies = [
  "tinyvec_macros",
 ]
@@ -2226,6 +2365,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
 
 [[package]]
+name = "uds_windows"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "486992108df0fe0160680af1941fe856c521be931d5a5ecccefe0de86dc47e4a"
+dependencies = [
+ "tempdir",
+ "winapi",
+]
+
+[[package]]
 name = "unicase"
 version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2236,9 +2385,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-bidi"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a01404663e3db436ed2746d9fefef640d868edae3cceb81c3b8d5732fda678f"
+checksum = "099b7128301d285f79ddd55b9a83d5e6b9e97c92e0ea0daebee7263e932de992"
 
 [[package]]
 name = "unicode-normalization"
@@ -2263,9 +2412,9 @@ checksum = "3ed742d4ea2bd1176e236172c8429aaf54486e7ac098db29ffe6529e0ce50973"
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+checksum = "957e51f3646910546462e67d5f7599b9e4fb8acdd304b087a6494730f9eebf04"
 
 [[package]]
 name = "uom"
@@ -2566,9 +2715,9 @@ dependencies = [
 
 [[package]]
 name = "zbus"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7bb86f3d4592e26a48b2719742aec94f8ae6238ebde20d98183ee185d1275e9a"
+checksum = "53819092b9db813b2c6168b097b4b13ad284d81c9f2b0165a0a1b190e505a1f3"
 dependencies = [
  "async-broadcast",
  "async-channel",
@@ -2595,6 +2744,7 @@ dependencies = [
  "serde_repr",
  "sha1",
  "static_assertions",
+ "uds_windows",
  "winapi",
  "zbus_macros",
  "zbus_names",
@@ -2603,9 +2753,9 @@ dependencies = [
 
 [[package]]
 name = "zbus_macros"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "36823cc10fddc3c6b19f048903262dacaf8274170e9a255784bdd8b4570a8040"
+checksum = "c7174ebe6722c280d6d132d694bb5664ce50a788cb70eeb518e7fc1ca095a114"
 dependencies = [
  "proc-macro-crate",
  "proc-macro2",
@@ -2627,9 +2777,9 @@ dependencies = [
 
 [[package]]
 name = "zvariant"
-version = "3.1.2"
+version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49ea5dc38b2058fae6a5b79009388143dadce1e91c26a67f984a0fc0381c8033"
+checksum = "e18ba99d71e03af262953f476071607da0c44e225236cf9b5b9f7f11f1d0b6b0"
 dependencies = [
  "byteorder",
  "enumflags2",
@@ -2641,9 +2791,9 @@ dependencies = [
 
 [[package]]
 name = "zvariant_derive"
-version = "3.1.2"
+version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c2cecc5a61c2a053f7f653a24cd15b3b0195d7f7ddb5042c837fb32e161fb7a"
+checksum = "9042892ebdca35261951a83d17bcbfd4d3d528cb3bde828498a9b306b50d05c0"
 dependencies = [
  "proc-macro-crate",
  "proc-macro2",
diff --git a/Cargo.toml b/Cargo.toml
index ca46148be..c1f954a09 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -83,6 +83,8 @@ yaml-rust = "0.4.5"
 
 process_control = { version = "3.4.0", features = ["crossbeam-channel"] }
 
+guess_host_triple = "0.1.3"
+home = "0.5.3"
 shell-words = "1.1.0"
 
 [dependencies.schemars]
diff --git a/docs/config/README.md b/docs/config/README.md
index 2e011535a..3d9be60de 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -2991,11 +2991,13 @@ The module will be shown if any of the following conditions are met:
 
 ### Variables
 
-| Variable | Example           | Description                          |
-| -------- | ----------------- | ------------------------------------ |
-| version  | `v1.43.0-nightly` | The version of `rustc`               |
-| symbol   |                   | Mirrors the value of option `symbol` |
-| style\*  |                   | Mirrors the value of option `style`  |
+| Variable  | Example           | Description                                  |
+| --------- | ----------------- | -------------------------------------------- |
+| version   | `v1.43.0-nightly` | The version of `rustc`                       |
+| numver    | `1.51.0`          | The numeric component of the `rustc` version |
+| toolchain | `beta`            | The toolchain version                        |
+| symbol    |                   | Mirrors the value of option `symbol`         |
+| style\*   |                   | Mirrors the value of option `style`          |
 
 *: This variable can only be used as a part of a style string
 
diff --git a/src/modules/rust.rs b/src/modules/rust.rs
index dddf3075e..5ccc54af1 100644
--- a/src/modules/rust.rs
+++ b/src/modules/rust.rs
@@ -1,601 +1,927 @@
-use std::fs;
-use std::path::Path;
-#[cfg(windows)]
-use std::path::PathBuf;
-use std::process::Output;
-
-use serde::Deserialize;
-
-use super::{Context, Module, ModuleConfig};
-
-use crate::configs::rust::RustConfig;
-use crate::formatter::{StringFormatter, VersionFormatter};
-use crate::utils::create_command;
-
-/// Creates a module with the current Rust version
-pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
-    let mut module = context.new_module("rust");
-    let config = RustConfig::try_load(module.config);
-
-    let is_rs_project = context
-        .try_begin_scan()?
-        .set_files(&config.detect_files)
-        .set_extensions(&config.detect_extensions)
-        .set_folders(&config.detect_folders)
-        .is_match();
-
-    if !is_rs_project {
-        return None;
-    }
-
-    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
-        formatter
-            .map_meta(|var, _| match var {
-                "symbol" => Some(config.symbol),
-                _ => None,
-            })
-            .map_style(|variable| match variable {
-                "style" => Some(Ok(config.style)),
-                _ => None,
-            })
-            .map(|variable| match variable {
-                // This may result in multiple calls to `get_module_version` when a user have
-                // multiple `$version` variables defined in `format`.
-                "version" => get_module_version(context, &config).map(Ok),
-                _ => None,
-            })
-            .parse(None, Some(context))
-    });
-
-    module.set_segments(match parsed {
-        Ok(segments) => segments,
-        Err(error) => {
-            log::warn!("Error in module `rust`:\n{}", error);
-            return None;
-        }
-    });
-
-    Some(module)
-}
-
-fn get_module_version(context: &Context, config: &RustConfig) -> Option<String> {
-    // `$CARGO_HOME/bin/rustc(.exe) --version` may attempt installing a rustup toolchain.
-    // https://github.com/starship/starship/issues/417
-    //
-    // To display appropriate versions preventing `rustc` from downloading toolchains, we have to
-    // check
-    // 1. `$RUSTUP_TOOLCHAIN`
-    // 2. `rustup override list`
-    // 3. `rust-toolchain` or `rust-toolchain.toml` in `.` or parent directories
-    // 4. `rustup default`
-    // as `rustup` does.
-    // https://github.com/rust-lang/rustup.rs/tree/eb694fcada7becc5d9d160bf7c623abe84f8971d#override-precedence
-    //
-    // Probably we have no other way to know whether any toolchain override is specified for the
-    // current directory. The following commands also cause toolchain installations.
-    // - `rustup show`
-    // - `rustup show active-toolchain`
-    // - `rustup which`
-    if let Some(toolchain) = env_rustup_toolchain(context)
-        .or_else(|| execute_rustup_override_list(context))
-        .or_else(|| find_rust_toolchain_file(context))
-        .or_else(|| execute_rustup_default(context))
-    {
-        match execute_rustup_run_rustc_version(context, &toolchain) {
-            RustupRunRustcVersionOutcome::RustcVersion(rustc_version) => {
-                format_rustc_version(&rustc_version, config.version_format)
-            }
-            RustupRunRustcVersionOutcome::ToolchainName(toolchain) => Some(toolchain),
-            RustupRunRustcVersionOutcome::RustupNotWorking => {
-                // If `rustup` is not in `$PATH` or cannot be executed for other reasons, we can
-                // safely execute `rustc --version`.
-                format_rustc_version(&execute_rustc_version(context)?, config.version_format)
-            }
-            RustupRunRustcVersionOutcome::Err => None,
-        }
-    } else {
-        format_rustc_version(&execute_rustc_version(context)?, config.version_format)
-    }
-}
-
-fn env_rustup_toolchain(context: &Context) -> Option<String> {
-    let val = context.get_env("RUSTUP_TOOLCHAIN")?;
-    Some(val.trim().to_owned())
-}
-
-fn execute_rustup_override_list(context: &Context) -> Option<String> {
-    extract_toolchain_from_rustup_override_list(
-        &context.exec_cmd("rustup", &["override", "list"])?.stdout,
-        &context.current_dir,
-    )
-}
-
-fn execute_rustup_default(context: &Context) -> Option<String> {
-    // `rustup default` output is:
-    //    stable-x86_64-apple-darwin (default)
-    context
-        .exec_cmd("rustup", &["default"])?
-        .stdout
-        .split_whitespace()
-        .next()
-        .map(str::to_owned)
-}
-
-fn extract_toolchain_from_rustup_override_list(stdout: &str, cwd: &Path) -> Option<String> {
-    if stdout == "no overrides\n" {
-        return None;
-    }
-
-    #[cfg(windows)]
-    let cwd = {
-        // use display version of path, also allows stripping \\?\
-        let cwd = cwd.to_string_lossy();
-        // rustup strips \\?\ prefix,
-        // so we do the same and convert back to a `Path`
-        PathBuf::from(cwd.strip_prefix(r"\\?\").unwrap_or(&cwd))
-    };
-
-    stdout
-        .lines()
-        .filter_map(|line| {
-            let (dir, toolchain) = line.split_once('\t')?;
-            Some((dir.trim(), toolchain.trim()))
-        })
-        // find most specific match
-        .filter(|(dir, _)| cwd.starts_with(dir))
-        .max_by_key(|(dir, _)| dir.len())
-        .map(|(_, toolchain)| toolchain.to_owned())
-}
-
-fn find_rust_toolchain_file(context: &Context) -> Option<String> {
-    // Look for 'rust-toolchain' or 'rust-toolchain.toml' as rustup does.
-    // for more information:
-    // https://rust-lang.github.io/rustup/overrides.html#the-toolchain-file
-    // for the implementation in 'rustup':
-    // https://github.com/rust-lang/rustup/blob/a45e4cd21748b04472fce51ba29999ee4b62bdec/src/config.rs#L631
-
-    #[derive(Deserialize)]
-    struct OverrideFile {
-        toolchain: ToolchainSection,
-    }
-
-    #[derive(Deserialize)]
-    struct ToolchainSection {
-        channel: Option<String>,
-    }
-
-    fn read_channel(path: &Path, only_toml: bool) -> Option<String> {
-        let contents = fs::read_to_string(path).ok()?;
-
-        match contents.lines().count() {
-            0 => None,
-            1 if !only_toml => Some(contents),
-            _ => {
-                toml::from_str::<OverrideFile>(&contents)
-                    .ok()?
-                    .toolchain
-                    .channel
-            }
-        }
-        .filter(|c| !c.trim().is_empty())
-        .map(|c| c.trim().to_owned())
-    }
-
-    if context
-        .dir_contents()
-        .map_or(false, |dir| dir.has_file("rust-toolchain"))
-    {
-        if let Some(toolchain) = read_channel(Path::new("rust-toolchain"), false) {
-            return Some(toolchain);
-        }
-    }
-
-    if context
-        .dir_contents()
-        .map_or(false, |dir| dir.has_file("rust-toolchain.toml"))
-    {
-        if let Some(toolchain) = read_channel(Path::new("rust-toolchain.toml"), true) {
-            return Some(toolchain);
-        }
-    }
-
-    let mut dir = &*context.current_dir;
-    loop {
-        if let Some(toolchain) = read_channel(&dir.join("rust-toolchain"), false) {
-            return Some(toolchain);
-        }
-        if let Some(toolchain) = read_channel(&dir.join("rust-toolchain.toml"), true) {
-            return Some(toolchain);
-        }
-        dir = dir.parent()?;
-    }
-}
-
-fn execute_rustup_run_rustc_version(
-    context: &Context,
-    toolchain: &str,
-) -> RustupRunRustcVersionOutcome {
-    create_command("rustup")
-        .and_then(|mut cmd| {
-            cmd.args(&["run", toolchain, "rustc", "--version"])
-                .current_dir(&context.current_dir)
-                .output()
-        })
-        .map(extract_toolchain_from_rustup_run_rustc_version)
-        .unwrap_or(RustupRunRustcVersionOutcome::RustupNotWorking)
-}
-
-fn extract_toolchain_from_rustup_run_rustc_version(output: Output) -> RustupRunRustcVersionOutcome {
-    if output.status.success() {
-        if let Ok(output) = String::from_utf8(output.stdout) {
-            return RustupRunRustcVersionOutcome::RustcVersion(output);
-        }
-    } else if let Ok(stderr) = String::from_utf8(output.stderr) {
-        if stderr.starts_with("error: toolchain '") && stderr.ends_with("' is not installed\n") {
-            let stderr = stderr
-                ["error: toolchain '".len()..stderr.len() - "' is not installed\n".len()]
-                .to_owned();
-            return RustupRunRustcVersionOutcome::ToolchainName(stderr);
-        }
-    }
-    RustupRunRustcVersionOutcome::Err
-}
-
-fn execute_rustc_version(context: &Context) -> Option<String> {
-    context
-        .exec_cmd("rustc", &["--version"])
-        .map(|o| o.stdout)
-        .filter(|s| !s.is_empty())
-}
-
-fn format_rustc_version(rustc_version: &str, version_format: &str) -> Option<String> {
-    let version = rustc_version
-        // split into ["rustc", "1.34.0", ...]
-        .split_whitespace()
-        // get down to "1.34.0"
-        .nth(1)?;
-
-    match VersionFormatter::format_version(version, version_format) {
-        Ok(formatted) => Some(formatted),
-        Err(error) => {
-            log::warn!("Error formatting `rust` version:\n{}", error);
-            Some(format!("v{}", version))
-        }
-    }
-}
-
-#[derive(Debug, PartialEq)]
-enum RustupRunRustcVersionOutcome {
-    RustcVersion(String),
-    ToolchainName(String),
-    RustupNotWorking,
-    Err,
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::context::{Shell, Target};
-    use once_cell::sync::Lazy;
-    use std::io;
-    use std::process::{ExitStatus, Output};
-
-    use super::*;
-
-    #[test]
-    fn test_extract_toolchain_from_rustup_override_list() {
-        static NO_OVERRIDES_INPUT: &str = "no overrides\n";
-        static NO_OVERRIDES_CWD: &str = "";
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(
-                NO_OVERRIDES_INPUT,
-                NO_OVERRIDES_CWD.as_ref(),
-            ),
-            None,
-        );
-
-        static OVERRIDES_INPUT: &str =
-            "/home/user/src/a                \t                beta-x86_64-unknown-linux-gnu\n\
-             /home/user/src/b                \t                nightly-x86_64-unknown-linux-gnu\n\
-             /home/user/src/b/d c            \t                stable-x86_64-pc-windows-msvc\n";
-        static OVERRIDES_CWD_A: &str = "/home/user/src/a/src";
-        static OVERRIDES_CWD_B: &str = "/home/user/src/b/tests";
-        static OVERRIDES_CWD_C: &str = "/home/user/src/c/examples";
-        static OVERRIDES_CWD_D: &str = "/home/user/src/b/d c/spaces";
-        static OVERRIDES_CWD_E: &str = "/home/user/src/b_and_more";
-        static OVERRIDES_CWD_F: &str = "/home/user/src/b";
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_A.as_ref()),
-            Some("beta-x86_64-unknown-linux-gnu".to_owned()),
-        );
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_B.as_ref()),
-            Some("nightly-x86_64-unknown-linux-gnu".to_owned()),
-        );
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_C.as_ref()),
-            None,
-        );
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_D.as_ref()),
-            Some("stable-x86_64-pc-windows-msvc".to_owned()),
-        );
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_E.as_ref()),
-            None,
-        );
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_F.as_ref()),
-            Some("nightly-x86_64-unknown-linux-gnu".to_owned()),
-        );
-    }
-
-    #[test]
-    #[cfg(windows)]
-    fn test_extract_toolchain_from_rustup_override_list_win() {
-        static OVERRIDES_INPUT: &str =
-            "C:\\src                \t                beta-x86_64-unknown-linux-gnu\n";
-        static OVERRIDES_CWD_A: &str = r"\\?\C:\src";
-        static OVERRIDES_CWD_B: &str = r"C:\src";
-
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_A.as_ref()),
-            Some("beta-x86_64-unknown-linux-gnu".to_owned()),
-        );
-
-        assert_eq!(
-            extract_toolchain_from_rustup_override_list(OVERRIDES_INPUT, OVERRIDES_CWD_B.as_ref()),
-            Some("beta-x86_64-unknown-linux-gnu".to_owned()),
-        );
-    }
-
-    #[cfg(any(unix, windows))]
-    #[test]
-    fn test_extract_toolchain_from_rustup_run_rustc_version() {
-        #[cfg(unix)]
-        use std::os::unix::process::ExitStatusExt as _;
-        #[cfg(windows)]
-        use std::os::windows::process::ExitStatusExt as _;
-
-        static RUSTC_VERSION: Lazy<Output> = Lazy::new(|| Output {
-            status: ExitStatus::from_raw(0),
-            stdout: b"rustc 1.34.0\n"[..].to_owned(),
-            stderr: vec![],
-        });
-        assert_eq!(
-            extract_toolchain_from_rustup_run_rustc_version(RUSTC_VERSION.clone()),
-            RustupRunRustcVersionOutcome::RustcVersion("rustc 1.34.0\n".to_owned()),
-        );
-
-        static TOOLCHAIN_NAME: Lazy<Output> = Lazy::new(|| Output {
-            status: ExitStatus::from_raw(1),
-            stdout: vec![],
-            stderr: b"error: toolchain 'channel-triple' is not installed\n"[..].to_owned(),