Merge branch 'staging' into ios-13

25 files changed, 447 insertions, 185 deletions

diff --git a/lib/default.nix b/lib/default.nix
index 7387e9d9f1ff..43b9ab5930c4 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -67,7 +67,7 @@ let
     inherit (trivial) id const pipe concat or and bitAnd bitOr bitXor
       bitNot boolToString mergeAttrs flip mapNullable inNixShell min max
       importJSON warn info showWarnings nixpkgsVersion version mod compare
-      splitByAndCompare functionArgs setFunctionArgs isFunction;
+      splitByAndCompare functionArgs setFunctionArgs isFunction toHexString toBaseDigits;
     inherit (fixedPoints) fix fix' converge extends composeExtensions
       makeExtensible makeExtensibleWithCustomName;
     inherit (attrsets) attrByPath hasAttrByPath setAttrByPath
diff --git a/lib/generators.nix b/lib/generators.nix
index efe6ea6031d3..abd237eb7d37 100644
--- a/lib/generators.nix
+++ b/lib/generators.nix
@@ -48,8 +48,10 @@ rec {
     else if isAttrs    v then err "attrsets" v
     # functions can’t be printed of course
     else if isFunction v then err "functions" v
-    # let’s not talk about floats. There is no sensible `toString` for them.
-    else if isFloat    v then err "floats" v
+    # Floats currently can't be converted to precise strings,
+    # condition warning on nix version once this isn't a problem anymore
+    # See https://github.com/NixOS/nix/pull/3480
+    else if isFloat    v then libStr.floatToString v
     else err "this value is" (toString v);
 
 
diff --git a/lib/licenses.nix b/lib/licenses.nix
index ed4d80fffac6..ee11966b0d53 100644
--- a/lib/licenses.nix
+++ b/lib/licenses.nix
@@ -28,7 +28,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "Academic Free License v3.0";
   };
 
-  agpl3 = spdx {
+  agpl3Only = spdx {
     spdxId = "AGPL-3.0-only";
     fullName = "GNU Affero General Public License v3.0 only";
   };
@@ -85,6 +85,11 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = ''Beerware License'';
   };
 
+  blueOak100 = spdx {
+    spdxId = "BlueOak-1.0.0";
+    fullName = "Blue Oak Model License 1.0.0";
+  };
+
   bsd0 = spdx {
     spdxId = "0BSD";
     fullName = "BSD Zero Clause License";
@@ -110,6 +115,11 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = ''BSD 4-clause "Original" or "Old" License'';
   };
 
+  bsdProtection = spdx {
+    spdxId = "BSD-Protection";
+    fullName = "BSD Protection License";
+  };
+
   bsl11 = {
     fullName = "Business Source License 1.1";
     url = "https://mariadb.com/bsl11";
@@ -281,12 +291,12 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "European Union Public License 1.2";
   };
 
-  fdl11 = spdx {
+  fdl11Only = spdx {
     spdxId = "GFDL-1.1-only";
     fullName = "GNU Free Documentation License v1.1 only";
   };
 
-  fdl12 = spdx {
+  fdl12Only = spdx {
     spdxId = "GFDL-1.2-only";
     fullName = "GNU Free Documentation License v1.2 only";
   };
@@ -296,7 +306,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "GNU Free Documentation License v1.2 or later";
   };
 
-  fdl13 = spdx {
+  fdl13Only = spdx {
     spdxId = "GFDL-1.3-only";
     fullName = "GNU Free Documentation License v1.3 only";
   };
@@ -327,7 +337,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     free = false;
   };
 
-  gpl1 = spdx {
+  gpl1Only = spdx {
     spdxId = "GPL-1.0-only";
     fullName = "GNU General Public License v1.0 only";
   };
@@ -337,7 +347,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "GNU General Public License v1.0 or later";
   };
 
-  gpl2 = spdx {
+  gpl2Only = spdx {
     spdxId = "GPL-2.0-only";
     fullName = "GNU General Public License v2.0 only";
   };
@@ -362,7 +372,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "GNU General Public License v2.0 or later";
   };
 
-  gpl3 = spdx {
+  gpl3Only = spdx {
     spdxId = "GPL-3.0-only";
     fullName = "GNU General Public License v3.0 only";
   };
@@ -426,6 +436,12 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
   };
 
   # Proprietary binaries; free to redistribute without modification.
+  databricks = {
+    fullName = "Databricks Proprietary License";
+    url = "https://pypi.org/project/databricks-connect";
+    free = false;
+  };
+
   issl = {
     fullName = "Intel Simplified Software License";
     url = "https://software.intel.com/en-us/license/intel-simplified-software-license";
@@ -437,7 +453,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "JasPer License";
   };
 
-  lgpl2 = spdx {
+  lgpl2Only = spdx {
     spdxId = "LGPL-2.0-only";
     fullName = "GNU Library General Public License v2 only";
   };
@@ -447,7 +463,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "GNU Library General Public License v2 or later";
   };
 
-  lgpl21 = spdx {
+  lgpl21Only = spdx {
     spdxId = "LGPL-2.1-only";
     fullName = "GNU Lesser General Public License v2.1 only";
   };
@@ -457,7 +473,7 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "GNU Lesser General Public License v2.1 or later";
   };
 
-  lgpl3 = spdx {
+  lgpl3Only = spdx {
     spdxId = "LGPL-3.0-only";
     fullName = "GNU Lesser General Public License v3.0 only";
   };
@@ -782,4 +798,16 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     spdxId = "ZPL-2.1";
     fullName = "Zope Public License 2.1";
   };
+} // {
+  # TODO: remove legacy aliases
+  agpl3 = lib.licenses.agpl3Only;
+  fdl11 = lib.licenses.fdl11Only;
+  fdl12 = lib.licenses.fdl12Only;
+  fdl13 = lib.licenses.fdl13Only;
+  gpl1 = lib.licenses.gpl1Only;
+  gpl2 = lib.licenses.gpl2Only;
+  gpl3 = lib.licenses.gpl3Only;
+  lgpl2 = lib.licenses.lgpl2Only;
+  lgpl21 = lib.licenses.lgpl21Only;
+  lgpl3 = lib.licenses.lgpl3Only;
 }
diff --git a/lib/modules.nix b/lib/modules.nix
index c18fec66c705..decb96ffe111 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -58,6 +58,23 @@ rec {
             default = check;
             description = "Whether to check whether all option definitions have matching declarations.";
           };
+
+          _module.freeformType = mkOption {
+            # Disallow merging for now, but could be implemented nicely with a `types.optionType`
+            type = types.nullOr (types.uniq types.attrs);
+            internal = true;
+            default = null;
+            description = ''
+              If set, merge all definitions that don't have an associated option
+              together using this type. The result then gets combined with the
+              values of all declared options to produce the final <literal>
+              config</literal> value.
+
+              If this is <literal>null</literal>, definitions without an option
+              will throw an error unless <option>_module.check</option> is
+              turned off.
+            '';
+          };
         };
 
         config = {
@@ -65,35 +82,55 @@ rec {
         };
       };
 
-      collected = collectModules
-        (specialArgs.modulesPath or "")
-        (modules ++ [ internalModule ])
-        ({ inherit config options lib; } // specialArgs);
-
-      options = mergeModules prefix (reverseList collected);
-
-      # Traverse options and extract the option values into the final
-      # config set.  At the same time, check whether all option
-      # definitions have matching declarations.
-      # !!! _module.check's value can't depend on any other config values
-      # without an infinite recursion. One way around this is to make the
-      # 'config' passed around to the modules be unconditionally unchecked,
-      # and only do the check in 'result'.
-      config = yieldConfig prefix options;
-      yieldConfig = prefix: set:
-        let res = removeAttrs (mapAttrs (n: v:
-          if isOption v then v.value
-          else yieldConfig (prefix ++ [n]) v) set) ["_definedNames"];
-        in
-        if options._module.check.value && set ? _definedNames then
-          foldl' (res: m:
-            foldl' (res: name:
-              if set ? ${name} then res else throw "The option `${showOption (prefix ++ [name])}' defined in `${m.file}' does not exist.")
-              res m.names)
-            res set._definedNames
-        else
-          res;
-      result = {
+      merged =
+        let collected = collectModules
+          (specialArgs.modulesPath or "")
+          (modules ++ [ internalModule ])
+          ({ inherit lib options config; } // specialArgs);
+        in mergeModules prefix (reverseList collected);
+
+      options = merged.matchedOptions;
+
+      config =
+        let
+
+          # For definitions that have an associated option
+          declaredConfig = mapAttrsRecursiveCond (v: ! isOption v) (_: v: v.value) options;
+
+          # If freeformType is set, this is for definitions that don't have an associated option
+          freeformConfig =
+            let
+              defs = map (def: {
+                file = def.file;
+                value = setAttrByPath def.prefix def.value;
+              }) merged.unmatchedDefns;
+            in if defs == [] then {}
+            else declaredConfig._module.freeformType.merge prefix defs;
+
+        in if declaredConfig._module.freeformType == null then declaredConfig
+          # Because all definitions that had an associated option ended in
+          # declaredConfig, freeformConfig can only contain the non-option
+          # paths, meaning recursiveUpdate will never override any value
+          else recursiveUpdate freeformConfig declaredConfig;
+
+      checkUnmatched =
+        if config._module.check && config._module.freeformType == null && merged.unmatchedDefns != [] then
+          let
+            firstDef = head merged.unmatchedDefns;
+            baseMsg = "The option `${showOption (prefix ++ firstDef.prefix)}' defined in `${firstDef.file}' does not exist.";
+          in
+            if attrNames options == [ "_module" ]
+              then throw ''
+                ${baseMsg}
+
+                However there are no options defined in `${showOption prefix}'. Are you sure you've
+                declared your options properly? This can happen if you e.g. declared your options in `types.submodule'
+                under `config' rather than `options'.
+              ''
+            else throw baseMsg
+        else null;
+
+      result = builtins.seq checkUnmatched {
         inherit options;
         config = removeAttrs config [ "_module" ];
         inherit (config) _module;
@@ -174,12 +211,16 @@ rec {
   /* Massage a module into canonical form, that is, a set consisting
      of ‘options’, ‘config’ and ‘imports’ attributes. */
   unifyModuleSyntax = file: key: m:
-    let addMeta = config: if m ? meta
-      then mkMerge [ config { meta = m.meta; } ]
-      else config;
+    let
+      addMeta = config: if m ? meta
+        then mkMerge [ config { meta = m.meta; } ]
+        else config;
+      addFreeformType = config: if m ? freeformType
+        then mkMerge [ config { _module.freeformType = m.freeformType; } ]
+        else config;
     in
     if m ? config || m ? options then
-      let badAttrs = removeAttrs m ["_file" "key" "disabledModules" "imports" "options" "config" "meta"]; in
+      let badAttrs = removeAttrs m ["_file" "key" "disabledModules" "imports" "options" "config" "meta" "freeformType"]; in
       if badAttrs != {} then
         throw "Module `${key}' has an unsupported attribute `${head (attrNames badAttrs)}'. This is caused by introducing a top-level `config' or `options' attribute. Add configuration attributes immediately on the top level instead, or move all of them (namely: ${toString (attrNames badAttrs)}) into the explicit `config' attribute."
       else
@@ -188,7 +229,7 @@ rec {
           disabledModules = m.disabledModules or [];
           imports = m.imports or [];
           options = m.options or {};
-          config = addMeta (m.config or {});
+          config = addFreeformType (addMeta (m.config or {}));
         }
     else
       { _file = m._file or file;
@@ -196,7 +237,7 @@ rec {
         disabledModules = m.disabledModules or [];
         imports = m.require or [] ++ m.imports or [];
         options = {};
-        config = addMeta (removeAttrs m ["_file" "key" "disabledModules" "require" "imports"]);
+        config = addFreeformType (addMeta (removeAttrs m ["_file" "key" "disabledModules" "require" "imports" "freeformType"]));
       };
 
   applyIfFunction = key: f: args@{ config, options, lib, ... }: if isFunction f then
@@ -233,7 +274,23 @@ rec {
      declarations in all modules, combining them into a single set.
      At the same time, for each option declaration, it will merge the
      corresponding option definitions in all machines, returning them
-     in the ‘value’ attribute of each option. */
+     in the ‘value’ attribute of each option.
+
+     This returns a set like
+       {
+         # A recursive set of options along with their final values
+         matchedOptions = {
+           foo = { _type = "option"; value = "option value of foo"; ... };
+           bar.baz = { _type = "option"; value = "option value of bar.baz"; ... };
+           ...
+         };
+         # A list of definitions that weren't matched by any option
+         unmatchedDefns = [
+           { file = "file.nix"; prefix = [ "qux" ]; value = "qux"; }
+           ...
+         ];
+       }
+  */
   mergeModules = prefix: modules:
     mergeModules' prefix modules
       (concatMap (m: map (config: { file = m._file; inherit config; }) (pushDownProperties m.config)) modules);
@@ -280,9 +337,9 @@ rec {
       defnsByName' = byName "config" (module: value:
           [{ inherit (module) file; inherit value; }]
         ) configs;
-    in
-    (flip mapAttrs declsByName (name: decls:
-      # We're descending into attribute ‘name’.
+
+      resultsByName = flip mapAttrs declsByName (name: decls:
+        # We're descending into attribute ‘name’.
         let
           loc = prefix ++ [name];
           defns = defnsByName.${name} or [];
@@ -291,7 +348,10 @@ rec {
         in
           if nrOptions == length decls then
             let opt = fixupOptionType loc (mergeOptionDecls loc decls);
-            in evalOptionValue loc opt defns'
+            in {
+              matchedOptions = evalOptionValue loc opt defns';
+              unmatchedDefns = [];
+            }
           else if nrOptions != 0 then
             let
               firstOption = findFirst (m: isOption m.options) "" decls;
@@ -299,9 +359,27 @@ rec {
             in
               throw "The option `${showOption loc}' in `${firstOption._file}' is a prefix of options in `${firstNonOption._file}'."
           else
-            mergeModules' loc decls defns
-      ))
-    // { _definedNames = map (m: { inherit (m) file; names = attrNames m.config; }) configs; };
+            mergeModules' loc decls defns);
+
+      matchedOptions = mapAttrs (n: v: v.matchedOptions) resultsByName;
+
+      # an attrset 'name' => list of unmatched definitions for 'name'
+      unmatchedDefnsByName =
+        # Propagate all unmatched definitions from nested option sets
+        mapAttrs (n: v: v.unmatchedDefns) resultsByName
+        # Plus the definitions for the current prefix that don't have a matching option
+        // removeAttrs defnsByName' (attrNames matchedOptions);
+    in {
+      inherit matchedOptions;
+
+      # Transforms unmatchedDefnsByName into a list of definitions
+      unmatchedDefns = concatLists (mapAttrsToList (name: defs:
+        map (def: def // {
+          # Set this so we know when the definition first left unmatched territory
+          prefix = [name] ++ (def.prefix or []);
+        }) defs
+      ) unmatchedDefnsByName);
+    };
 
   /* Merge multiple option declarations into a single declaration.  In
      general, there should be only one declaration of each option.
@@ -535,7 +613,6 @@ rec {
         if tp.name == "option set" || tp.name == "submodule" then
           throw "The option ${showOption loc} uses submodules without a wrapping type, in ${showFiles opt.declarations}."
         else if optionSetIn "attrsOf" then types.attrsOf (types.submodule options)
-        else if optionSetIn "loaOf"   then types.loaOf   (types.submodule options)
         else if optionSetIn "listOf"  then types.listOf  (types.submodule options)
         else if optionSetIn "nullOr"  then types.nullOr  (types.submodule options)
         else tp;
diff --git a/lib/sources.nix b/lib/sources.nix
index ed9bce485300..776fcc32052b 100644
--- a/lib/sources.nix
+++ b/lib/sources.nix
@@ -145,10 +145,14 @@ rec {
            # packed-refs file, so we have to grep through it:
            then
              let fileContent = readFile packedRefsName;
-                 matchRef    = match (".*\n([^\n ]*) " + file + "\n.*") fileContent;
-             in if  matchRef == null
+                 matchRef = builtins.match "([a-z0-9]+) ${file}";
+                 isRef = s: builtins.isString s && (matchRef s) != null;
+                 # there is a bug in libstdc++ leading to stackoverflow for long strings:
+                 # https://github.com/NixOS/nix/issues/2147#issuecomment-659868795
+                 refs = builtins.filter isRef (builtins.split "\n" fileContent);
+             in if refs == []
                 then throw ("Could not find " + file + " in " + packedRefsName)
-                else lib.head matchRef
+                else lib.head (matchRef (lib.head refs))
 
            else throw ("Not a .git directory: " + path);
     in readCommitFromFile "HEAD";
diff --git a/lib/strings.nix b/lib/strings.nix
index 74e3eaa0722d..9fa9f023561e 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -612,6 +612,22 @@ rec {
   */
   fixedWidthNumber = width: n: fixedWidthString width "0" (toString n);
 
+  /* Convert a float to a string, but emit a warning when precision is lost
+     during the conversion
+
+     Example:
+       floatToString 0.000001
+       => "0.000001"
+       floatToString 0.0000001
+       => trace: warning: Imprecise conversion from float to string 0.000000
+          "0.000000"
+  */
+  floatToString = float: let
+    result = toString float;
+    precise = float == builtins.fromJSON result;
+  in if precise then result
+    else lib.warn "Imprecise conversion from float to string ${result}" result;
+
   /* Check whether a value can be coerced to a string */
   isCoercibleToString = x:
     builtins.elem (builtins.typeOf x) [ "path" "string" "null" "int" "float" "bool" ] ||
@@ -673,14 +689,15 @@ rec {
             "/prefix/nix-profiles-library-paths.patch"
             "/prefix/compose-search-path.patch" ]
   */
-  readPathsFromFile = rootPath: file:
-    let
-      lines = lib.splitString "\n" (builtins.readFile file);
-      removeComments = lib.filter (line: line != "" && !(lib.hasPrefix "#" line));
-      relativePaths = removeComments lines;
-      absolutePaths = builtins.map (path: rootPath + "/${path}") relativePaths;
-    in
-      absolutePaths;
+  readPathsFromFile = lib.warn "lib.readPathsFromFile is deprecated, use a list instead"
+    (rootPath: file:
+      let
+        lines = lib.splitString "\n" (builtins.readFile file);
+        removeComments = lib.filter (line: line != "" && !(lib.hasPrefix "#" line));
+        relativePaths = removeComments lines;
+        absolutePaths = builtins.map (path: rootPath + "/${path}") relativePaths;
+      in
+        absolutePaths);
 
   /* Read the contents of a file removing the trailing \n
 
diff --git a/lib/systems/architectures.nix b/lib/systems/architectures.nix
new file mode 100644
index 000000000000..9d1c29fd9f0b
--- /dev/null
+++ b/lib/systems/architectures.nix
@@ -0,0 +1,77 @@
+{ lib }:
+
+rec {
+  # platform.gcc.arch to its features (as in /proc/cpuinfo)
+  features = {
+    default        = [ ];
+    # x86_64 Intel
+    westmere       = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes"                                    ];
+    sandybridge    = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx"                              ];
+    ivybridge      = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx"                              ];
+    haswell        = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx" "avx2"          "fma"        ];
+    broadwell      = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx" "avx2"          "fma"        ];
+    skylake        = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx" "avx2"          "fma"        ];
+    skylake-avx512 = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx" "avx2" "avx512" "fma"        ];
+    # x86_64 AMD
+    btver1         = [ "sse3" "ssse3" "sse4_1" "sse4_2"                                                  ];
+    btver2         = [ "sse3" "ssse3" "sse4_1" "sse4_2"         "aes" "avx"                              ];
+    bdver1         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx"                 "fma" "fma4" ];
+    bdver2         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx"                 "fma" "fma4" ];
+    bdver3         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx"                 "fma" "fma4" ];
+    bdver4         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx" "avx2"          "fma" "fma4" ];
+    znver1         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx" "avx2"          "fma"        ];
+    znver2         = [ "sse3" "ssse3" "sse4_1" "sse4_2" "sse4a" "aes" "avx" "avx2"          "fma"        ];
+    # other
+    armv5te        = [ ];
+    armv6          = [ ];
+    armv7-a        = [ ];
+    armv8-a        = [ ];
+    mips32         = [ ];
+    loongson2f     = [ ];
+  };
+
+  # a superior CPU has all the features of an inferior and is able to build and test code for it
+  inferiors = {
+    # x86_64 Intel
+    default        = [ ];
+    westmere       = [ ];
+    sandybridge    = [ "westmere"    ] ++ inferiors.westmere;
+    ivybridge      = [ "sandybridge" ] ++ inferiors.sandybridge;
+    haswell        = [ "ivybridge"   ] ++ inferiors.ivybridge;
+    broadwell      = [ "haswell"     ] ++ inferiors.haswell;
+    skylake        = [ "broadwell"   ] ++ inferiors.broadwell;
+    skylake-avx512 = [ "skylake"     ] ++ inferiors.skylake;
+    # x86_64 AMD
+    btver1         = [ ];
+    btver2         = [ ]; # TODO: fill this (need testing)
+    bdver1         = [ ]; # TODO: fill this (need testing)
+    bdver2         = [ ]; # TODO: fill this (need testing)
+    bdver3         = [ ]; # TODO: fill this (need testing)
+    bdver4         = [ ]; # TODO: fill this (need testing)
+    znver1         = [ ]; # TODO: fill this (need testing)
+    znver2         = [ ]; # TODO: fill this (need testing)
+    # other
+    armv5te        = [ ];
+    armv6          = [ ];
+    armv7-a        = [ ];
+    armv8-a        = [ ];
+    mips32         = [ ];
+    loongson2f     = [ ];
+  };
+
+  predicates = let
+    featureSupport = feature: x: builtins.elem feature features.${x};
+  in {
+    sse3Support    = featureSupport "sse3";
+    ssse3Support   = featureSupport "ssse3";
+    sse4_1Support  = featureSupport "sse4_1";
+    sse4_2Support  = featureSupport "sse4_2";
+    sse4_aSupport  = featureSupport "sse4a";
+    avxSupport     = featureSupport "avx";
+    avx2Support    = featureSupport "avx2";
+    avx512Support  = featureSupport "avx512";
+    aesSupport     = featureSupport "aes";
+    fmaSupport     = featureSupport "fma";
+    fma4Support    = featureSupport "fma4";
+  };
+}
diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index 210674cc6399..9939743157e7 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -7,6 +7,7 @@ rec {
   inspect = import ./inspect.nix { inherit lib; };
   platforms = import ./platforms.nix { inherit lib; };
   examples = import ./examples.nix { inherit lib; };
+  architectures = import ./architectures.nix { inherit lib; };
 
   # Elaborate a `localSystem` or `crossSystem` so that it contains everything
   # necessary.
@@ -32,6 +33,7 @@ rec {
         /**/ if final.isDarwin              then "libSystem"
         else if final.isMinGW               then "msvcrt"
         else if final.isWasi                then "wasilibc"
+        else if final.isRedox               then "relibc"
         else if final.isMusl                then "musl"
         else if final.isUClibc              then "uclibc"
         else if final.isAndroid             then "bionic"
@@ -65,6 +67,7 @@ rec {
           freebsd = "FreeBSD";
           openbsd = "OpenBSD";
           wasi = "Wasi";
+          redox = "Redox";
           genode = "Genode";
         }.${final.parsed.kernel.name} or null;
 
@@ -74,6 +77,7 @@ rec {
          # uname -r
          release = null;
       };
+      isStatic = final.isWasm || final.isRedox;
 
       kernelArch =
         if final.isAarch32 then "arm"
@@ -123,6 +127,7 @@ rec {
         else throw "Don't know how to run ${final.config} executables.";
 
     } // mapAttrs (n: v: v final.parsed) inspect.predicates
+      // mapAttrs (n: v: v final.platform.gcc.arch or "default") architectures.predicates
       // args;
   in assert final.useAndroidPrebuilt -> final.isAndroid;
      assert lib.foldl
diff --git a/lib/systems/doubles.nix b/lib/systems/doubles.nix
index a839b3d3d573..fb7d722e737e 100644
--- a/lib/systems/doubles.nix
+++ b/lib/systems/doubles.nix
@@ -22,6 +22,8 @@ let
 
     "wasm64-wasi" "wasm32-wasi"
 
+    "x86_64-redox"
+
     "powerpc64le-linux"
 
     "riscv32-linux" "riscv64-linux"
@@ -36,7 +38,7 @@ let
 
     "js-ghcjs"
 
-    "aarch64-genode" "x86_64-genode"
+    "aarch64-genode" "i686-genode" "x86_64-genode"
   ];
 
   allParsed = map parse.mkSystemFromString all;
@@ -69,6 +71,7 @@ in {
   openbsd = filterDoubles predicates.isOpenBSD;
   unix    = filterDoubles predicates.isUnix;
   wasi    = filterDoubles predicates.isWasi;
+  redox   = filterDoubles predicates.isRedox;
   windows = filterDoubles predicates.isWindows;
   genode  = filterDoubles predicates.isGenode;
 
diff --git a/lib/systems/examples.nix b/lib/systems/examples.nix
index 3b32130f388a..5b90fdca5244 100644
--- a/lib/systems/examples.nix
+++ b/lib/systems/examples.nix
@@ -46,7 +46,7 @@ rec {
 
   armv7a-android-prebuilt = {
     config = "armv7a-unknown-linux-androideabi";
-    sdkVer = "24";
+    sdkVer = "29";
     ndkVer = "18b";
     platform = platforms.armv7a-android;
     useAndroidPrebuilt = true;
@@ -54,7 +54,7 @@ rec {
 
   aarch64-android-prebuilt = {
     config = "aarch64-unknown-linux-android";
-    sdkVer = "24";
+    sdkVer = "29";
     ndkVer = "18b";
     platform = platforms.aarch64-multiplatform;
     useAndroidPrebuilt = true;
@@ -164,6 +164,15 @@ rec {
   };
 
   #
+  # Redox
+  #
+
+  x86_64-unknown-redox = {
+    config = "x86_64-unknown-redox";
+    libc = "relibc";
+  };
+
+  #
   # Darwin
   #
 
diff --git a/lib/systems/inspect.nix b/lib/systems/inspect.nix
index 90a1fb6d80c2..8fa630572509 100644
--- a/lib/systems/inspect.nix
+++ b/lib/systems/inspect.nix
@@ -33,7 +33,7 @@ rec {
 
     isBSD          = { kernel = { families = { inherit (kernelFamilies) bsd; }; }; };
     isDarwin       = { kernel = { families = { inherit (kernelFamilies) darwin; }; }; };
-    isUnix         = [ isBSD isDarwin isLinux isSunOS isCygwin ];
+    isUnix         = [ isBSD isDarwin isLinux isSunOS isCygwin isRedox ];
 
     isMacOS        = { kernel = kernels.macos; };
     isiOS          = { kernel = kernels.ios; };
@@ -46,6 +46,7 @@ rec {
     isCygwin       = { kernel = kernels.windows; abi = abis.cygnus; };
     isMinGW        = { kernel = kernels.windows; abi = abis.gnu; };
     isWasi         = { kernel = kernels.wasi; };
+    isRedox        = { kernel = kernels.redox; };
     isGhcjs        = { kernel = kernels.ghcjs; };
     isGenode       = { kernel = kernels.genode; };
     isNone         = { kernel = kernels.none; };
diff --git a/lib/systems/parse.nix b/lib/systems/parse.nix
index 648e7c270240..6bd44a007466 100644
--- a/lib/systems/parse.nix
+++ b/lib/systems/parse.nix
@@ -277,6 +277,7 @@ rec {
     openbsd = { execFormat = elf;     families = { inherit bsd; }; };
     solaris = { execFormat = elf;     families = { }; };
     wasi    = { execFormat = wasm;    families = { }; };
+    redox   = { execFormat = elf;     families = { }; };
     windows = { execFormat = pe;      families = { }; };
     ghcjs   = { execFormat = unknown; families = { }; };
     genode  = { execFormat = elf;     families = { }; };
@@ -390,6 +391,8 @@ rec {
         then { cpu = elemAt l 0; vendor = elemAt l 1; kernel = "windows";                    }
       else if (elemAt l 2 == "wasi")
         then { cpu = elemAt l 0; vendor = elemAt l 1; kernel = "wasi";                       }
+      else if (elemAt l 2 == "redox")
+        then { cpu = elemAt l 0; vendor = elemAt l 1; kernel = "redox";                      }
       else if hasPrefix "netbsd" (elemAt l 2)
         then { cpu = elemAt l 0; vendor = elemAt l 1;    kernel = elemAt l 2;                }
       else if (elem (