pkgsMusl.haskell.compiler.ghc8107Binary: Remove now-incorrect gmp dependency.

GHC HQ switched the musl bindists from gmp to `integer-simple`
with GHC >= 8.10.6, but this was not reflected in the nixpkgs update:

* commit 6f1242469a: ghc: 8.10.5-binary -> 8.10.7-binary
  From PR #135453

See also #130441.

pkgs/development/compilers/ghc/8.10.2-binary.nix

@@ -46,6 +46,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           # The i686-linux bindist provided by GHC HQ is currently built on Debian 9,
           # which link it against `libtinfo.so.5` (ncurses 5).
           # Other bindists are linked `libtinfo.so.6` (ncurses 6).
@@ -59,6 +60,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
         ];
       };
@@ -69,6 +71,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
         ];
       };
@@ -79,6 +82,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
           { nixPackage = numactl; fileToCheckFor = null; }
         ];
@@ -90,6 +94,7 @@ let
         };
         exePathForLibraryCheck = null; # we don't have a library check for darwin yet
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = null; }
           { nixPackage = libiconv; fileToCheckFor = null; }
         ];
@@ -104,6 +109,7 @@ let
         };
         exePathForLibraryCheck = "bin/ghc";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           # In contrast to glibc builds, the musl-bindist uses `libncursesw.so.*`
           # instead of `libtinfo.so.*.`
           { nixPackage = ncurses6; fileToCheckFor = "libncursesw.so.6"; }
@@ -121,11 +127,8 @@ let
 
   libPath =
     lib.makeLibraryPath (
-      [
-        gmp
-      ]
       # Add arch-specific libraries.
-      ++ map ({ nixPackage, ... }: nixPackage) binDistUsed.archSpecificLibraries
+      map ({ nixPackage, ... }: nixPackage) binDistUsed.archSpecificLibraries
     );
 
   libEnvVar = lib.optionalString stdenv.hostPlatform.isDarwin "DY"
@@ -140,6 +143,12 @@ stdenv.mkDerivation rec {
 
   src = fetchurl binDistUsed.src;
 
+  # Note that for GHC 8.10 versions <= 8.10.5, the GHC HQ musl bindist
+  # has a `gmp` dependency:
+  # https://gitlab.haskell.org/ghc/ghc/-/commit/8306501020cd66f683ad9c215fa8e16c2d62357d
+  # Related nixpkgs issues:
+  # * https://github.com/NixOS/nixpkgs/pull/130441#issuecomment-922452843
+
   nativeBuildInputs = [ perl ];
   propagatedBuildInputs =
     lib.optionals useLLVM [ llvmPackages.llvm ]
@@ -147,6 +156,9 @@ stdenv.mkDerivation rec {
     # libgmp is (see not [musl bindists have no .buildinfo]), we need
     # to propagate `gmp`, otherwise programs built by this ghc will
     # fail linking with `cannot find -lgmp` errors.
+    # Concrete cases are listed in:
+    #     https://github.com/NixOS/nixpkgs/pull/130441#issuecomment-922459988
+    #
     # Also, as of writing, the release pages of musl bindists claim
     # that they use `integer-simple` and do not require `gmp`; however
     # that is incorrect, so `gmp` is required until a release has been
@@ -154,6 +166,12 @@ stdenv.mkDerivation rec {
     # (Note that for packaging the `-binary` compiler, nixpkgs does not care
     # about whether or not `gmp` is used; this comment is just here to explain
     # why the `gmp` dependency exists despite what the release page says.)
+    #
+    # For GHC >= 8.10.6, `gmp` was switched out for `integer-simple`
+    # (https://gitlab.haskell.org/ghc/ghc/-/commit/8306501020cd66f683ad9c215fa8e16c2d62357d),
+    # fixing the above-mentioned release issue,
+    # and for GHC >= 9.* it is not clear as of writing whether that switch
+    # will be made there too.
     ++ lib.optionals stdenv.hostPlatform.isMusl [ gmp ]; # musl bindist needs this
 
   # Set LD_LIBRARY_PATH or equivalent so that the programs running as part

pkgs/development/compilers/ghc/8.10.7-binary.nix

@@ -47,6 +47,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           # The i686-linux bindist provided by GHC HQ is currently built on Debian 9,
           # which link it against `libtinfo.so.5` (ncurses 5).
           # Other bindists are linked `libtinfo.so.6` (ncurses 6).
@@ -60,6 +61,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
         ];
       };
@@ -70,6 +72,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
         ];
       };
@@ -80,6 +83,7 @@ let
         };
         exePathForLibraryCheck = "ghc/stage2/build/tmp/ghc-stage2";
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = "libtinfo.so.6"; }
           { nixPackage = numactl; fileToCheckFor = null; }
         ];
@@ -91,6 +95,7 @@ let
         };
         exePathForLibraryCheck = null; # we don't have a library check for darwin yet
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = null; }
           { nixPackage = libiconv; fileToCheckFor = null; }
         ];
@@ -102,6 +107,7 @@ let
         };
         exePathForLibraryCheck = null; # we don't have a library check for darwin yet
         archSpecificLibraries = [
+          { nixPackage = gmp; fileToCheckFor = null; }
           { nixPackage = ncurses6; fileToCheckFor = null; }
           { nixPackage = libiconv; fileToCheckFor = null; }
         ];
@@ -116,6 +122,8 @@ let
         };
         exePathForLibraryCheck = "bin/ghc";
         archSpecificLibraries = [
+          # No `gmp` here, since this is an `integer-simple` bindist.
+
           # In contrast to glibc builds, the musl-bindist uses `libncursesw.so.*`
           # instead of `libtinfo.so.*.`
           { nixPackage = ncurses6; fileToCheckFor = "libncursesw.so.6"; }
@@ -133,11 +141,8 @@ let
 
   libPath =
     lib.makeLibraryPath (
-      [
-        gmp
-      ]
       # Add arch-specific libraries.
-      ++ map ({ nixPackage, ... }: nixPackage) binDistUsed.archSpecificLibraries
+      map ({ nixPackage, ... }: nixPackage) binDistUsed.archSpecificLibraries
     );
 
   libEnvVar = lib.optionalString stdenv.hostPlatform.isDarwin "DY"
@@ -152,21 +157,21 @@ stdenv.mkDerivation rec {
 
   src = fetchurl binDistUsed.src;
 
+  # Note that for GHC 8.10 versions >= 8.10.6, the GHC HQ musl bindist
+  # uses `integer-simple` and has no `gmp` dependency:
+  # https://gitlab.haskell.org/ghc/ghc/-/commit/8306501020cd66f683ad9c215fa8e16c2d62357d
+  # Related nixpkgs issues:
+  # * https://github.com/NixOS/nixpkgs/pull/130441#issuecomment-922452843
+  # TODO: When this file is copied to `ghc-9.*-binary.nix`, determine whether
+  #       the GHC 9 branch also switched from `gmp` to `integer-simple` via the
+  #       currently-open issue:
+  #           https://gitlab.haskell.org/ghc/ghc/-/issues/20059
+  #       and update this comment accordingly.
+
   nativeBuildInputs = [ perl ];
   propagatedBuildInputs =
     lib.optionals useLLVM [ llvmPackages.llvm ]
-    # Because musl bindists currently provide no way to tell where
+    ;
-    # libgmp is (see not [musl bindists have no .buildinfo]), we need
-    # to propagate `gmp`, otherwise programs built by this ghc will
-    # fail linking with `cannot find -lgmp` errors.
-    # Also, as of writing, the release pages of musl bindists claim
-    # that they use `integer-simple` and do not require `gmp`; however
-    # that is incorrect, so `gmp` is required until a release has been
-    # made that includes https://gitlab.haskell.org/ghc/ghc/-/issues/20059.
-    # (Note that for packaging the `-binary` compiler, nixpkgs does not care
-    # about whether or not `gmp` is used; this comment is just here to explain
-    # why the `gmp` dependency exists despite what the release page says.)
-    ++ lib.optionals stdenv.hostPlatform.isMusl [ gmp ]; # musl bindist needs this
 
   # Set LD_LIBRARY_PATH or equivalent so that the programs running as part
   # of the bindist installer can find the libraries they expect.
@@ -227,9 +232,9 @@ stdenv.mkDerivation rec {
       patchShebangs ghc-${version}/configure
     '' +
     # We have to patch the GMP paths for the integer-gmp package.
-    # Note [musl bindists have no .buildinfo]
+    # Note that musl bindists do not contain them,
-    # Note that musl bindists do not contain them; unclear if that's intended;
     # see: https://gitlab.haskell.org/ghc/ghc/-/issues/20073#note_363231
+    # However, musl bindists >= 8.10.6 use `integer-simple`, not `gmp`.
     ''
       find . -name integer-gmp.buildinfo \
           -exec sed -i "s@extra-lib-dirs: @extra-lib-dirs: ${gmp.out}/lib@" {} \;