Fix postgresql musl: disable pythonSupport/tclSupport to reduce outputs

The postgresql build for musl cross-compilation was producing 7 outputs
(out, dev, doc, lib, man, plpython3, pltcl) because pythonSupport and
tclSupport default to true when !isStatic && canExecute. Since
pkgsCross.musl64 doesn't set isStatic=true, these were enabled.

Each extra output widens the nix-copy window between build completion
and output transfer, exacerbating the min-free GC race on darwin
builders where outputs vanish before they can be copied to hydra.

Reducing from 7 to 5 outputs (removing plpython3 and pltcl) should
help. These PL extensions are unnecessary for musl cross-builds anyway.

Author: angerman

CLAUDE.md

@@ -68,13 +68,14 @@ pkgs.runCommand "devx" {} ''
 - **Jobset:** input-output-hk-devx:pullrequest-220
 - **URL:** https://ci.zw3rk.com/jobset/input-output-hk-devx/pullrequest-220
 
-### Latest Update (2026-02-13)
+### Latest Update (2026-02-14)
 
-**Eval 384** (commit 02fd4d4): 563/643 succeeded, 75 failed, 5 building.
-Root causes: gcc-14.3.0 (34, infra), postgresql-musl (31), hadrian (10 cached).
-nghttp3, libev, tzdata ALL FIXED in this eval.
+**Eval 389** (commit c62060b): 568/643 succeeded, 59 dep-failed, 16 building.
+Root causes: postgresql-musl GC race (both arches), GCC-14.3.0 (infra), hadrian (stale cache).
+All code-level build failures (nghttp3, libev, tzdata, openssl, postgresql LTO) are FIXED.
 
-**Latest commit** ca89062 — disables LTO for postgresql (fixes .ltrans link failure).
+**Latest commit** (pending push) — disables pythonSupport/tclSupport for postgresql musl,
+reducing outputs from 7 (out,dev,doc,lib,man,plpython3,pltcl) to 5 (out,dev,doc,lib,man).
 
 **Summary of all fixes applied (in overlay order):**
 1. **happy disallowGhcReference** (build-fixes): Disable GHC reference check for
@@ -90,22 +91,28 @@ nghttp3, libev, tzdata ALL FIXED in this eval.
 6. **PostgreSQL musl** (musl overlay): Multiple issues fixed:
    - `jitSupport = false`: removes --with-llvm and LLVM build inputs
    - `perlSupport = false`: musl perl lacks shared libperl
-   - `hardeningDisable = ["lto"]`: GCC LTO + GNU ld is broken for postgresql
-     (undefined refs in .ltrans); the nixpkgs stdenv switch to LLVM bintools
-     exists specifically for ld.lld, just disable LTO instead
+   - `pythonSupport = false`: removes plpython3 output (unnecessary for musl cross)
+   - `tclSupport = false`: removes pltcl output (unnecessary for musl cross)
+   - `NIX_CFLAGS_COMPILE = "-fno-lto"`: GCC LTO + GNU ld is broken for postgresql
+     (.ltrans link failures). Can't use hardeningDisable=["lto"] because "lto" is
+     not a recognized hardening flag on musl cross stdenv.
+   - `llvmPackages_20` override to prevent LLVM stdenv switch (avoids LLVM dep)
    - `outputChecks = {}`: removes unconditional LLVM disallowedRequisites refs
    - `doCheck = false`: dict_snowball.so relocation fails in musl static
+   - `separateDebugInfo = false`: eliminates massive -debug output that causes
+     nix-copy transfer to race against builder min-free auto-GC
 
 **Remaining infra issues:**
 - **GCC 14.3.0** (34 Windows builds): `/usr/include` missing — darwin builders
   claim x86_64-linux support but GCC's fixincludes expects real Linux host.
   Fix: infra change to builder system type config, not a devx overlay.
-- **hadrian** (10 builds): stale failure cache despite outputs existing in store.
-  Queue runner keeps re-caching. May need investigation of cache mechanism.
+- **hadrian**: stale failure cache despite outputs existing in store.
+  Queue runner keeps re-caching after restart.
 
 **Key discovery:** nixpkgs-2511 `pkgsCross.musl64` doesn't set `isStatic = true`.
 This causes ALL optional features guarded by `!isStatic` to default to true,
-including jitSupport, perlSupport, and the LTO stdenv switch in postgresql.
+including jitSupport, perlSupport, pythonSupport, tclSupport, and the
+LTO stdenv switch in postgresql.
 
 The -env job generation using `devShellTools` is working correctly.
 

flake.nix

@@ -130,17 +130,23 @@
            #
            # 1. jitSupport defaults true → pulls in LLVM build inputs.
            # 2. perlSupport defaults true → musl perl lacks shared libperl.
-           # 3. generic.nix switches to LLVM stdenv+bintools for LTO when
+           # 3. pythonSupport/tclSupport default true → adds plpython3/pltcl
+           #    outputs. These are unnecessary for musl cross-builds and
+           #    each extra output widens the nix-copy window, exacerbating
+           #    the min-free GC race on darwin builders.
+           # 4. generic.nix switches to LLVM stdenv+bintools for LTO when
            #    GCC is used. Cross-compiled LLVM 20 OOMs on darwin builders.
            #    We override llvmPackages_20 to prevent the switch (avoids
            #    LLVM dependency), then explicitly disable LTO with -fno-lto
            #    since GCC LTO + GNU ld is broken for postgresql (.ltrans
            #    link failures). Can't use hardeningDisable=["lto"] because
            #    "lto" is not a recognized hardening flag on musl cross.
-           # 4. outputChecks unconditionally reference llvmPackages.llvm.
+           # 5. outputChecks unconditionally reference llvmPackages.llvm.
            postgresql = (prev.postgresql.override {
              jitSupport = false;
              perlSupport = false;
+             pythonSupport = false;
+             tclSupport = false;
              # Prevent the LTO stdenv switch: provide normal GCC-based
              # musl stdenv as llvmPackages_20, making the switch a no-op.
              llvmPackages_20 = prev.llvmPackages_20 // {
@@ -155,11 +161,6 @@
              };
              doCheck = false;
              outputChecks = {};
-             # Disable separateDebugInfo to avoid massive -debug output
-             # with hundreds of symlinks. The debug output size causes
-             # nix-copy transfers to take too long, racing against the
-             # builder's min-free auto-GC which deletes the outputs
-             # before they can be transferred to the hydra machine.
              separateDebugInfo = false;
            });
          });