Merge branch 'master' into add-newer-xcode-hashes

22 files changed, 596 insertions, 190 deletions

diff --git a/lib/customisation.nix b/lib/customisation.nix
index dc5dd7691976..37a7951896b0 100644
--- a/lib/customisation.nix
+++ b/lib/customisation.nix
@@ -217,4 +217,31 @@ rec {
         };
     in self;
 
+  /* Like the above, but aims to support cross compilation. It's still ugly, but
+     hopefully it helps a little bit. */
+  makeScopeWithSplicing = splicePackages: newScope: otherSplices: keep: f:
+    let
+      spliced = splicePackages {
+        pkgsBuildBuild = otherSplices.selfBuildBuild;
+        pkgsBuildHost = otherSplices.selfBuildHost;
+        pkgsBuildTarget = otherSplices.selfBuildTarget;
+        pkgsHostHost = otherSplices.selfHostHost;
+        pkgsHostTarget = self; # Not `otherSplices.selfHostTarget`;
+        pkgsTargetTarget = otherSplices.selfTargetTarget;
+      } // keep self;
+      self = f self // {
+        newScope = scope: newScope (spliced // scope);
+        callPackage = newScope spliced; # == self.newScope {};
+        # N.B. the other stages of the package set spliced in are *not*
+        # overridden.
+        overrideScope = g: makeScopeWithSplicing
+          splicePackages
+          newScope
+          otherSplices
+          keep
+          (lib.fixedPoints.extends g f);
+        packages = f;
+      };
+    in self;
+
 }
diff --git a/lib/debug.nix b/lib/debug.nix
index 2879f72ed2ba..ea6aed60ab43 100644
--- a/lib/debug.nix
+++ b/lib/debug.nix
@@ -14,9 +14,25 @@
 */
 { lib }:
 let
-  inherit (builtins) trace isAttrs isList isInt
-          head substring attrNames;
-  inherit (lib) id elem isFunction;
+  inherit (lib)
+    isInt
+    attrNames
+    isList
+    isAttrs
+    substring
+    addErrorContext
+    attrValues
+    concatLists
+    concatStringsSep
+    const
+    elem
+    generators
+    head
+    id
+    isDerivation
+    isFunction
+    mapAttrs
+    trace;
 in
 
 rec {
@@ -94,7 +110,7 @@ rec {
        trace: { a = { b = {…}; }; }
        => null
    */
-  traceSeqN = depth: x: y: with lib;
+  traceSeqN = depth: x: y:
     let snip = v: if      isList  v then noQuotes "[…]" v
                   else if isAttrs v then noQuotes "{…}" v
                   else v;
@@ -149,7 +165,7 @@ rec {
   */
   runTests =
     # Tests to run
-    tests: lib.concatLists (lib.attrValues (lib.mapAttrs (name: test:
+    tests: concatLists (attrValues (mapAttrs (name: test:
     let testsToRun = if tests ? tests then tests.tests else [];
     in if (substring 0 4 name == "test" ||  elem name testsToRun)
        && ((testsToRun == []) || elem name tests.tests)
@@ -176,9 +192,9 @@ rec {
           + "and will be removed in the next release. "
           + "Please use more specific concatenation "
           + "for your uses (`lib.concat(Map)StringsSep`)." )
-    (lib.concatStringsSep "; " (map (x: "${x}=") (attrNames a)));
+    (concatStringsSep "; " (map (x: "${x}=") (attrNames a)));
 
-  showVal = with lib;
+  showVal =
     trace ( "Warning: `showVal` is deprecated "
           + "and will be removed in the next release, "
           + "please use `traceSeqN`" )
@@ -226,7 +242,7 @@ rec {
     trace ( "Warning: `addErrorContextToAttrs` is deprecated "
           + "and will be removed in the next release. "
           + "Please use `builtins.addErrorContext` directly." )
-    (lib.mapAttrs (a: v: lib.addErrorContext "while evaluating ${a}" v) attrs);
+    (mapAttrs (a: v: addErrorContext "while evaluating ${a}" v) attrs);
 
   # example: (traceCallXml "myfun" id 3) will output something like
   # calling myfun arg 1: 3 result: 3
diff --git a/lib/default.nix b/lib/default.nix
index 44076d295176..f985266ed938 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -5,11 +5,11 @@
  */
 let
 
-  inherit (import ./fixed-points.nix {}) makeExtensible;
+  inherit (import ./fixed-points.nix { inherit lib; }) makeExtensible;
 
   lib = makeExtensible (self: let
     callLibs = file: import file { lib = self; };
-  in with self; {
+  in {
 
     # often used, or depending on very little
     trivial = callLibs ./trivial.nix;
@@ -54,7 +54,7 @@ let
     filesystem = callLibs ./filesystem.nix;
 
     # back-compat aliases
-    platforms = systems.doubles;
+    platforms = self.systems.doubles;
 
     # linux kernel configuration
     kernel = callLibs ./kernel.nix;
@@ -63,14 +63,14 @@ let
       deepSeq elem elemAt filter genericClosure genList getAttr
       hasAttr head isAttrs isBool isInt isList isString length
       lessThan listToAttrs pathExists readFile replaceStrings seq
-      stringLength sub substring tail;
-    inherit (trivial) id const pipe concat or and bitAnd bitOr bitXor
-      bitNot boolToString mergeAttrs flip mapNullable inNixShell min max
+      stringLength sub substring tail trace;
+    inherit (self.trivial) id const pipe concat or and bitAnd bitOr bitXor
+      bitNot boolToString mergeAttrs flip mapNullable inNixShell isFloat min max
       importJSON importTOML warn info showWarnings nixpkgsVersion version mod compare
       splitByAndCompare functionArgs setFunctionArgs isFunction toHexString toBaseDigits;
-    inherit (fixedPoints) fix fix' converge extends composeExtensions
-      makeExtensible makeExtensibleWithCustomName;
-    inherit (attrsets) attrByPath hasAttrByPath setAttrByPath
+    inherit (self.fixedPoints) fix fix' converge extends composeExtensions
+      composeManyExtensions makeExtensible makeExtensibleWithCustomName;
+    inherit (self.attrsets) attrByPath hasAttrByPath setAttrByPath
       getAttrFromPath attrVals attrValues getAttrs catAttrs filterAttrs
       filterAttrsRecursive foldAttrs collect nameValuePair mapAttrs
       mapAttrs' mapAttrsToList mapAttrsRecursive mapAttrsRecursiveCond
@@ -79,13 +79,13 @@ let
       recursiveUpdate matchAttrs overrideExisting getOutput getBin
       getLib getDev getMan chooseDevOutputs zipWithNames zip
       recurseIntoAttrs dontRecurseIntoAttrs;
-    inherit (lists) singleton forEach foldr fold foldl foldl' imap0 imap1
+    inherit (self.lists) singleton forEach foldr fold foldl foldl' imap0 imap1
       concatMap flatten remove findSingle findFirst any all count
       optional optionals toList range partition zipListsWith zipLists
       reverseList listDfs toposort sort naturalSort compareLists take
       drop sublist last init crossLists unique intersectLists
       subtractLists mutuallyExclusive groupBy groupBy';
-    inherit (strings) concatStrings concatMapStrings concatImapStrings
+    inherit (self.strings) concatStrings concatMapStrings concatImapStrings
       intersperse concatStringsSep concatMapStringsSep
       concatImapStringsSep makeSearchPath makeSearchPathOutput
       makeLibraryPath makeBinPath optionalString
@@ -97,19 +97,19 @@ let
       nameFromURL enableFeature enableFeatureAs withFeature
       withFeatureAs fixedWidthString fixedWidthNumber isStorePath
       toInt readPathsFromFile fileContents;
-    inherit (stringsWithDeps) textClosureList textClosureMap
+    inherit (self.stringsWithDeps) textClosureList textClosureMap
       noDepEntry fullDepEntry packEntry stringAfter;
-    inherit (customisation) overrideDerivation makeOverridable
+    inherit (self.customisation) overrideDerivation makeOverridable
       callPackageWith callPackagesWith extendDerivation hydraJob
-      makeScope;
-    inherit (meta) addMetaAttrs dontDistribute setName updateName
+      makeScope makeScopeWithSplicing;
+    inherit (self.meta) addMetaAttrs dontDistribute setName updateName
       appendToName mapDerivationAttrset setPrio lowPrio lowPrioSet hiPrio
       hiPrioSet;
-    inherit (sources) pathType pathIsDirectory cleanSourceFilter
+    inherit (self.sources) pathType pathIsDirectory cleanSourceFilter
       cleanSource sourceByRegex sourceFilesBySuffices
       commitIdFromGitRepo cleanSourceWith pathHasContext
       canCleanSource pathIsRegularFile pathIsGitRepo;
-    inherit (modules) evalModules unifyModuleSyntax
+    inherit (self.modules) evalModules unifyModuleSyntax
       applyIfFunction mergeModules
       mergeModules' mergeOptionDecls evalOptionValue mergeDefinitions
       pushDownProperties dischargeProperties filterOverrides
@@ -119,21 +119,21 @@ let
       mkAliasAndWrapDefinitions fixMergeModules mkRemovedOptionModule
       mkRenamedOptionModule mkMergedOptionModule mkChangedOptionModule
       mkAliasOptionModule doRename;
-    inherit (options) isOption mkEnableOption mkSinkUndeclaredOptions
+    inherit (self.options) isOption mkEnableOption mkSinkUndeclaredOptions
       mergeDefaultOption mergeOneOption mergeEqualOption getValues
       getFiles optionAttrSetToDocList optionAttrSetToDocList'
       scrubOptionValue literalExample showOption showFiles
       unknownModule mkOption;
-    inherit (types) isType setType defaultTypeMerge defaultFunctor
+    inherit (self.types) isType setType defaultTypeMerge defaultFunctor
       isOptionType mkOptionType;
-    inherit (asserts)
+    inherit (self.asserts)
       assertMsg assertOneOf;
-    inherit (debug) addErrorContextToAttrs traceIf traceVal traceValFn
+    inherit (self.debug) addErrorContextToAttrs traceIf traceVal traceValFn
       traceXMLVal traceXMLValMarked traceSeq traceSeqN traceValSeq
       traceValSeqFn traceValSeqN traceValSeqNFn traceShowVal
       traceShowValMarked showVal traceCall traceCall2 traceCall3
       traceValIfNot runTests testAllTrue traceCallXml attrNamesToStr;
-    inherit (misc) maybeEnv defaultMergeArg defaultMerge foldArgs
+    inherit (self.misc) maybeEnv defaultMergeArg defaultMerge foldArgs
       maybeAttrNullable maybeAttr ifEnable checkFlag getValue
       checkReqs uniqList uniqListExt condConcat lazyGenericClosure
       innerModifySumArgs modifySumArgs innerClosePropagation
@@ -143,7 +143,7 @@ let
       mergeAttrsByFuncDefaultsClean mergeAttrBy
       fakeHash fakeSha256 fakeSha512
       nixType imap;
-    inherit (versions)
+    inherit (self.versions)
       splitVersion;
   });
 in lib
diff --git a/lib/filesystem.nix b/lib/filesystem.nix
index fc35a1a72c64..0a1275e547cf 100644
--- a/lib/filesystem.nix
+++ b/lib/filesystem.nix
@@ -42,4 +42,16 @@
               type = (builtins.readDir parent).${base} or null;
           in file == /. || type == "directory";
     in go (if isDir then file else parent);
+
+
+  # listFilesRecursive: Path -> [ Path ]
+  #
+  # Given a directory, return a flattened list of all files within it recursively.
+  listFilesRecursive = dir: lib.flatten (lib.mapAttrsToList (name: type:
+    if type == "directory" then
+      lib.filesystem.listFilesRecursive (dir + "/${name}")
+    else
+      dir + "/${name}"
+  ) (builtins.readDir dir));
+
 }
diff --git a/lib/fixed-points.nix b/lib/fixed-points.nix
index 968930526a63..f998bc74e1db 100644
--- a/lib/fixed-points.nix
+++ b/lib/fixed-points.nix
@@ -1,4 +1,4 @@
-{ ... }:
+{ lib, ... }:
 rec {
   # Compute the fixed point of the given function `f`, which is usually an
   # attribute set that expects its final, non-recursive representation as an
@@ -77,6 +77,15 @@ rec {
           super' = super // fApplied;
       in fApplied // g self super';
 
+  # Compose several extending functions of the type expected by 'extends' into
+  # one where changes made in preceding functions are made available to
+  # subsequent ones.
+  #
+  # composeManyExtensions : [packageSet -> packageSet -> packageSet] -> packageSet -> packageSet -> packageSet
+  #                          ^final        ^prev         ^overrides     ^final        ^prev         ^overrides
+  composeManyExtensions =
+    lib.foldr (x: y: composeExtensions x y) (self: super: {});
+
   # Create an overridable, recursive attribute set. For example:
   #
   #     nix-repl> obj = makeExtensible (self: { })
diff --git a/lib/licenses.nix b/lib/licenses.nix
index a704a6884c7d..ebeb1377339b 100644
--- a/lib/licenses.nix
+++ b/lib/licenses.nix
@@ -18,6 +18,11 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "Abstyles License";
   };
 
+  afl20 = spdx {
+    spdxId = "AFL-2.0";
+    fullName = "Academic Free License v2.0";
+  };
+
   afl21 = spdx {
     spdxId = "AFL-2.1";
     fullName = "Academic Free License v2.1";
@@ -392,6 +397,11 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "Historic Permission Notice and Disclaimer";
   };
 
+  hpndSellVariant = spdx {
+    fullName = "Historical Permission Notice and Disclaimer - sell variant";
+    spdxId = "HPND-sell-variant";
+  };
+
   # Intel's license, seems free
   iasl = {
     fullName = "iASL";
@@ -613,6 +623,12 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
     fullName = "Open Software License 3.0";
   };
 
+  parity70 = spdx {
+    spdxId = "Parity-7.0.0";
+    fullName = "Parity Public License 7.0.0";
+    url = "https://paritylicense.com/versions/7.0.0.html";
+  };
+
   php301 = spdx {
     spdxId = "PHP-3.01";
     fullName = "PHP License v3.01";
@@ -801,14 +817,54 @@ lib.mapAttrs (n: v: v // { shortName = n; }) {
   };
 } // {
   # 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;
+  agpl3 = spdx {
+    spdxId = "AGPL-3.0";
+    fullName = "GNU Affero General Public License v3.0";
+    deprecated = true;
+  };
+  fdl11 = spdx {
+    spdxId = "GFDL-1.1";
+    fullName = "GNU Free Documentation License v1.1";
+    deprecated = true;
+  };
+  fdl12 = spdx {
+    spdxId = "GFDL-1.2";
+    fullName = "GNU Free Documentation License v1.2";
+    deprecated = true;
+  };
+  fdl13 = spdx {
+    spdxId = "GFDL-1.3";
+    fullName = "GNU Free Documentation License v1.3";
+    deprecated = true;
+  };
+  gpl1 = spdx {
+    spdxId = "GPL-1.0";
+    fullName = "GNU General Public License v1.0";
+    deprecated = true;
+  };
+  gpl2 = spdx {
+    spdxId = "GPL-2.0";
+    fullName = "GNU General Public License v2.0";
+    deprecated = true;
+  };
+  gpl3 = spdx {
+    spdxId = "GPL-3.0";
+    fullName = "GNU General Public License v3.0";
+    deprecated = true;
+  };
+  lgpl2 = spdx {
+    spdxId = "LGPL-2.0";
+    fullName = "GNU Library General Public License v2";
+    deprecated = true;
+  };
+  lgpl21 = spdx {
+    spdxId = "LGPL-2.1";
+    fullName = "GNU Lesser General Public License v2.1";
+    deprecated = true;
+  };
+  lgpl3 = spdx {
+    spdxId = "LGPL-3.0";
+    fullName = "GNU Lesser General Public License v3.0";
+    deprecated = true;
+  };
 }
diff --git a/lib/lists.nix b/lib/lists.nix
index f424946c72cd..06cee2eb112a 100644
--- a/lib/lists.nix
+++ b/lib/lists.nix
@@ -1,9 +1,9 @@
 # General list operations.
 
 { lib }:
-with lib.trivial;
 let
   inherit (lib.strings) toInt;
+  inherit (lib.trivial) compare min;
 in
 rec {
 
@@ -640,13 +640,7 @@ rec {
        unique [ 3 2 3 4 ]
        => [ 3 2 4 ]
    */
-  unique = list:
-    if list == [] then
-      []
-    else
-      let
-        x = head list;
-      in [x] ++ unique (remove x list);
+ unique = foldl' (acc: e: if elem e acc then acc else acc ++ [ e ]) [];
 
   /* Intersects list 'e' and another list. O(nm) complexity.
 
diff --git a/lib/modules.nix b/lib/modules.nix
index df3a2ad17e5f..3f2bfd478b0d 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -1,12 +1,53 @@
 { lib }:
 
-with lib.lists;
-with lib.strings;
-with lib.trivial;
-with lib.attrsets;
-with lib.options;
-with lib.debug;
-with lib.types;
+let
+  inherit (lib)
+    all
+    any
+    attrByPath
+    attrNames
+    catAttrs
+    concatLists
+    concatMap
+    count
+    elem
+    filter
+    findFirst
+    flip
+    foldl
+    foldl'
+    getAttrFromPath
+    head
+    id
+    imap1
+    isAttrs
+    isBool
+    isFunction
+    isString
+    length
+    mapAttrs
+    mapAttrsToList
+    mapAttrsRecursiveCond
+    min
+    optional
+    optionalAttrs
+    optionalString
+    recursiveUpdate
+    reverseList sort
+    setAttrByPath
+    toList
+    types
+    warn
+    ;
+  inherit (lib.options)
+    isOption
+    mkOption
+    showDefs
+    showFiles
+    showOption
+    unknownModule
+    ;
+in
 
 rec {
 
@@ -224,7 +265,7 @@ rec {
       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: ${toString (attrNames badAttrs)}) into the explicit `config' attribute."
       else
-        { _file = m._file or file;
+        { _file = toString m._file or file;
           key = toString m.key or key;
           disabledModules = m.disabledModules or [];
           imports = m.imports or [];
@@ -232,7 +273,7 @@ rec {
           config = addFreeformType (addMeta (m.config or {}));
         }
     else
-      { _file = m._file or file;
+      { _file = toString m._file or file;
         key = toString m.key or key;
         disabledModules = m.disabledModules or [];
         imports = m.require or [] ++ m.imports or [];
@@ -616,7 +657,7 @@ rec {
   fixupOptionType = loc: opt:
     let
       options = opt.options or
-        (throw "Option `${showOption loc'}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}.");
+        (throw "Option `${showOption loc}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}.");
       f = tp:
         let optionSetIn = type: (tp.name == type) && (tp.functor.wrapped.name == "optionSet");
         in
@@ -719,7 +760,7 @@ rec {
 
        mkRemovedOptionModule [ "boot" "loader" "grub" "bootDevice" ] "<replacement instructions>"
 
-     causes a warning if the user defines boot.loader.grub.bootDevice.
+     causes a assertion if the user defines boot.loader.grub.bootDevice.
 
      replacementInstructions is a string that provides instructions on
      how to achieve the same functionality without the removed option,
diff --git a/lib/options.nix b/lib/options.nix
index 5b7482c80937..87cd8b797969 100644
--- a/lib/options.nix
+++ b/lib/options.nix
@@ -1,11 +1,40 @@
 # Nixpkgs/NixOS option handling.
 { lib }:
 
-with lib.trivial;
-with lib.lists;
-with lib.attrsets;
-with lib.strings;
-
+let
+  inherit (lib)
+    all
+    collect
+    concatLists
+    concatMap
+    elemAt
+    filter
+    foldl'
+    head
+    isAttrs
+    isBool
+    isDerivation
+    isFunction
+    isInt
+    isList
+    isString
+    length
+    mapAttrs
+    optional
+    optionals
+    take
+    ;
+  inherit (lib.attrsets)
+    optionalAttrs
+    ;
+  inherit (lib.strings)
+    concatMapStrings
+    concatStringsSep
+    ;
+  inherit (lib.types)
+    mkOptionType
+    ;
+in
 rec {
 
   /* Returns true when the given argument is an option
@@ -110,7 +139,7 @@ rec {
     # Return early if we only have one element
     # This also makes it work for functions, because the foldl' below would try
     # to compare the first element with itself, which is false for functions
-    else if length defs == 1 then (elemAt defs 0).value
+    else if length defs == 1 then (head defs).value
     else (foldl' (first: def:
       if def.value != first.value then
         throw "The option `${showOption loc}' has conflicting definition values:${showDefs [ first def ]}"
diff --git a/lib/sources.nix b/lib/sources.nix
index 776fcc32052b..1a3afcae67da 100644
--- a/lib/sources.nix
+++ b/lib/sources.nix
@@ -1,16 +1,33 @@
 # Functions for copying sources to the Nix store.
 { lib }:
 
+let
+  inherit (builtins)
+    hasContext
+    match
+    readDir
+    split
+    storeDir
+    tryEval
+    ;
+  inherit (lib)
+    filter
+    getAttr
+    isString
+    pathExists
+    readFile
+    ;
+in
 rec {
 
   # Returns the type of a path: regular (for file), symlink, or directory
-  pathType = p: with builtins; getAttr (baseNameOf p) (readDir (dirOf p));
+  pathType = p: getAttr (baseNameOf p) (readDir (dirOf p));
 
   # Returns true if the path exists and is a directory, false otherwise
-  pathIsDirectory = p: if builtins.pathExists p then (pathType p) == "directory" else false;
+  pathIsDirectory = p: if pathExists p then (pathType p) == "directory" else false;
 
   # Returns true if the path exists and is a regular file, false otherwise
-  pathIsRegularFile = p: if builtins.pathExists p then (pathType p) == "regular" else false;
+  pathIsRegularFile = p: if pathExists p then (pathType p) == "regular" else false;
 
   # Bring in a path as a source, filtering out all Subversion and CVS
   # directories, as well as backup files (*~).
@@ -19,8 +36,8 @@ rec {
     (baseName == ".git" || type == "directory" && (baseName == ".svn" || baseName == "CVS" || baseName == ".hg")) ||
     # Filter out editor backup / swap files.
     lib.hasSuffix "~" baseName ||
-    builtins.match "^\\.sw[a-z]$" baseName != null ||
-    builtins.match "^\\..*\\.sw[a-z]$" baseName != null ||
+    match "^\\.sw[a-z]$" baseName != null ||
+    match "^\\..*\\.sw[a-z]$" baseName != null ||
 
     # Filter out generates files.
     lib.hasSuffix ".o" baseName ||
@@ -89,7 +106,7 @@ rec {
     in lib.cleanSourceWith {
       filter = (path: type:
         let relPath = lib.removePrefix (toString origSrc + "/") (toString path);
-        in lib.any (re: builtins.match re relPath != null) regexes);
+        in lib.any (re: match re relPath != null) regexes);
       inherit src;
     };
 
@@ -102,13 +119,12 @@ rec {
       in type == "directory" || lib.any (ext: lib.hasSuffix ext base) exts;
     in cleanSourceWith { inherit filter; src = path; };
 
-  pathIsGitRepo = path: (builtins.tryEval (commitIdFromGitRepo path)).success;
+  pathIsGitRepo = path: (tryEval (commitIdFromGitRepo path)).success;
 
   # Get the commit id of a git repo
   # Example: commitIdFromGitRepo <nixpkgs/.git>
   commitIdFromGitRepo =
     let readCommitFromFile = file: path:
-      with builtins;
         let fileName       = toString path + "/" + file;
             packedRefsName = toString path + "/packed-refs";
             absolutePath   = base: path:
@@ -145,11 +161,11 @@ rec {
            # packed-refs file, so we have to grep through it:
            then
              let fileContent = readFile packedRefsName;
-                 matchRef = builtins.match "([a-z0-9]+) ${file}";
-                 isRef = s: builtins.isString s && (matchRef s) != null;
+                 matchRef = match "([a-z0-9]+) ${file}";
+                 isRef = s: 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);
+                 refs = filter isRef (split "\n" fileContent);
              in if refs == []
                 then throw ("Could not find " + file + " in " + packedRefsName)
                 else lib.head (matchRef (lib.head refs))
@@ -157,7 +173,7 @@ rec {
            else throw ("Not a .git directory: " + path);
     in readCommitFromFile "HEAD";
 
-  pathHasContext = builtins.hasContext or (lib.hasPrefix builtins.storeDir);
+  pathHasContext = builtins.hasContext or (lib.hasPrefix storeDir);
 
   canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
 }
diff --git a/lib/strings-with-deps.nix b/lib/strings-with-deps.nix
index e3336983428f..7b88b018da57 100644
--- a/lib/strings-with-deps.nix
+++ b/lib/strings-with-deps.nix
@@ -41,10 +41,15 @@ Usage:
   [1] maybe this behaviour should be removed to keep things simple (?)
 */
 
-with lib.lists;
-with lib.attrsets;
-with lib.strings;
-
+let
+  inherit (lib)
+    concatStringsSep
+    head
+    isAttrs
+    listToAttrs
+    tail
+    ;
+in
 rec {
 
   /* !!! The interface of this function is kind of messed up, since
diff --git a/lib/strings.nix b/lib/strings.nix
index 9fa9f023561e..5010d9159cb8 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -8,7 +8,29 @@ in
 
 rec {
 
-  inherit (builtins) stringLength substring head tail isString replaceStrings;
+  inherit (builtins)
+    compareVersions
+    elem
+    elemAt
+    filter
+    fromJSON
+    head
+    isInt
+    isList
+    isString
+    match
+    parseDrvName
+    readFile
+    replaceStrings
+    split
+    storeDir
+    stringLength
+    substring
+    tail
+    toJSON
+    typeOf
+    unsafeDiscardStringContext
+    ;
 
   /* Concatenate a list of strings.
 
@@ -120,7 +142,7 @@ rec {
     subDir:
     # List of base paths
     paths:
-    concatStringsSep ":" (map (path: path + "/" + subDir) (builtins.filter (x: x != null) paths));
+    concatStringsSep ":" (map (path: path + "/" + subDir) (filter (x: x != null) paths));
 
   /* Construct a Unix-style search path by appending the given
      `subDir` to the specified `output` of each of the packages. If no
@@ -313,7 +335,17 @@ rec {
        escapeNixString "hello\${}\n"
        => "\"hello\\\${}\\n\""
   */
-  escapeNixString = s: escape ["$"] (builtins.toJSON s);
+  escapeNixString = s: escape ["$"] (toJSON s);
+
+  /* Turn a string into an exact regular expression
+
+     Type: string -> string
+
+     Example:
+       escapeRegex "[^a-z]*"
+       => "\\[\\^a-z]\\*"
+  */
+  escapeRegex = escape (stringToCharacters "\\[{()^$?*+|.");
 
   /* Quotes a string if it can't be used as an identifier directly.
 
@@ -327,7 +359,7 @@ rec {
   */
   escapeNixIdentifier = s:
     # Regex from https://github.com/NixOS/nix/blob/d048577909e383439c2549e849c5c2f2016c997e/src/libexpr/lexer.l#L91
-    if builtins.match "[a-zA-Z_][a-zA-Z0-9_'-]*" s != null
+    if match "[a-zA-Z_][a-zA-Z0-9_'-]*" s != null
     then s else escapeNixString s;
 
   # Obsolete - use replaceStrings instead.
@@ -386,8 +418,6 @@ rec {
   /* Cut a string with a separator and produces a list of strings which
      were separated by this separator.
 
-     NOTE: this function is not performant and should never be used.
-
      Example:
        splitString "." "foo.bar.baz"
        => [ "foo" "bar" "baz" ]
@@ -396,26 +426,11 @@ rec {
   */
   splitString = _sep: _s:
     let
-      sep = addContextFrom _s _sep;
-      s = addContextFrom _sep _s;
-      sepLen = stringLength sep;
-      sLen = stringLength s;
-      lastSearch = sLen - sepLen;
-      startWithSep = startAt:
-        substring startAt sepLen s == sep;
-
-      recurse = index: startAt:
-        let cutUntil = i: [(substring startAt (i - startAt) s)]; in
-        if index <= lastSearch then
-          if startWithSep index then
-            let restartAt = index + sepLen; in
-            cutUntil index ++ recurse restartAt restartAt
-          else
-            recurse (index + 1) startAt
-        else
-          cutUntil sLen;
+      sep = builtins.unsafeDiscardStringContext _sep;
+      s