chore(nix): switch to standard nix pin

+ iohk nix was too slow in ci without caching

Author: rasheedja

.github/workflows/haskell-nix.yml

@@ -1,4 +1,4 @@
-name: Haskell CI with Nix
+name: Nix CI
 
 on:
   push:
@@ -10,8 +10,6 @@ permissions:
 jobs:
   nix-ci:
     runs-on: ubuntu-latest
-    env:
-      NIX_CONFIG: accept-flake-config = true
 
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
@@ -25,34 +23,50 @@ jobs:
       - name: Enable Nix cache
         uses: DeterminateSystems/magic-nix-cache-action@565684385bcd71bad329742eefe8d12f2e765b39 # v13
 
-      - name: Show toolchain versions from nix shell
-        shell: bash
+      - name: Debug library environment
         run: |
-          nix develop --command bash -lc 'ghc --numeric-version'
-          nix develop --command bash -lc 'cabal --numeric-version'
-          nix develop --command bash -lc 'stack --numeric-version || true'
-          nix develop --command bash -lc 'fourmolu --version'
-
-      - name: Check formatting
-        run: nix develop --command make format-check
-
-      - name: Check cabal file
-        run: nix develop --command make cabal-check
-
-      - name: Update cabal package index
-        run: nix develop --command make cabal-update
-
-      - name: Configure the build
-        run: nix develop --command make configure
-
-      - name: Build dependencies
-        run: nix develop --command make deps
-
-      - name: Build the package
-        run: nix develop --command make build
-
-      - name: Run tests
-        run: nix develop --command make test
-
-      - name: Build documentation
-        run: nix develop --command make docs
+          nix develop --command bash -c '
+            echo "=== LD_LIBRARY_PATH ==="
+            echo "$LD_LIBRARY_PATH" | tr ":" "\n"
+            echo ""
+            echo "=== Files in each LD_LIBRARY_PATH dir ==="
+            echo "$LD_LIBRARY_PATH" | tr ":" "\n" | while read dir; do
+              echo "--- $dir ---"
+              ls "$dir"/*.so* 2>/dev/null || echo "(no .so files)"
+            done
+            echo ""
+            echo "=== GHC CC from settings ==="
+            ghc_libdir=$(ghc --print-libdir)
+            python3 -c "
+            data = open(\"$ghc_libdir/settings\").read()
+            for line in eval(data):
+              if \"compiler\" in line[0].lower() or \"ld\" in line[0].lower() or \"linker\" in line[0].lower():
+                print(f\"{line[0]}: {line[1]}\")
+            "
+            echo ""
+            echo "=== CC wrapper nix-support ==="
+            ghc_cc=$(python3 -c "data=open(\"$ghc_libdir/settings\").read(); print(dict(eval(data))[\"C compiler command\"])")
+            echo "CC: $ghc_cc"
+            wrapper_dir=$(dirname "$ghc_cc")/../nix-support
+            echo "=== libc-ldflags ==="
+            cat "$wrapper_dir/libc-ldflags" 2>/dev/null || echo "(not found)"
+            echo "=== dynamic-linker ==="
+            cat "$wrapper_dir/dynamic-linker" 2>/dev/null || echo "(not found)"
+            echo "=== cc-ldflags ==="
+            cat "$wrapper_dir/cc-ldflags" 2>/dev/null || echo "(not found)"
+            echo "=== NIX_LDFLAGS from env ==="
+            echo "$NIX_LDFLAGS"
+            echo ""
+            echo "=== Test: compile and run minimal C program ==="
+            cat > /tmp/test.c << CEOF
+            #include <stdio.h>
+            int main() { printf("hello from test binary\n"); return 0; }
+          CEOF
+            $ghc_cc -o /tmp/test_bin /tmp/test.c && ldd /tmp/test_bin && /tmp/test_bin
+            echo ""
+            echo "=== Test: compile with -lbz2 ==="
+            $ghc_cc -o /tmp/test_bz2 /tmp/test.c -lbz2 2>&1 && ldd /tmp/test_bz2 && /tmp/test_bz2
+          '
+
+      - name: Build and test
+        run: nix develop --command make ci

.github/workflows/update-flake.yml

@@ -13,8 +13,6 @@ permissions:
 jobs:
   update-flake:
     runs-on: ubuntu-latest
-    env:
-      NIX_CONFIG: accept-flake-config = true
 
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2