Validate local Guile fix on FreeBSD

docs/PROGRESS.md

@@ -66,13 +66,63 @@ Current assessment:
 - the next practical step is to validate a workaround or patch in Guile so subprocess helpers stop crashing
 - after that, continue with Phase 1.2 (minimal native build environment / GNU Hello)
 
+## 2026-04-01 — Phase 1.1 follow-up: local Guile build validated the fix
+
+Completed work:
+
+- installed the additional build tooling needed for a local Guile checkout build:
+  - `autoconf`
+  - `automake`
+  - `libtool`
+  - `gettext-tools`
+  - `texinfo`
+  - `help2man`
+  - `gperf`
+  - `pkgconf`
+- confirmed a FreeBSD-specific bootstrap quirk:
+  - Guile `autogen.sh` needs GNU `m4`
+  - FreeBSD base `/usr/bin/m4` is not sufficient
+  - `M4=gm4 ./autogen.sh` works
+- built a disposable validation copy from `~/repos/guile`
+- confirmed `~/repos/guile` already contains upstream commit:
+  - `eb828801f621d3e130b6fe88cfc4acaa69b98a03`
+  - `Don't use posix_spawn_file_actions_addclosefrom_np with glib posix_spawn`
+- updated the local test harnesses so they can test non-system Guile builds:
+  - `tests/guile/run-phase1-verification.sh`
+  - `tests/guile/run-subprocess-diagnostics.sh`
+  - both now accept `GUILE_BIN`
+  - both now prepend the sibling `../lib` directory to `LD_LIBRARY_PATH` when a matching local `libguile-3.0.so.1` exists
+  - subprocess diagnostics now supports `EXPECT_GUILE_SUBPROCESS_CRASH=0` for fixed builds
+- validated that the packaged Guile still reproduces the crash
+- validated that the locally built Guile succeeds for:
+  - `system*`
+  - `spawn`
+  - `open-pipe*`
+- re-ran the broader Phase 1.1 Scheme verification suite successfully against the local Guile build
+- wrote the results to `docs/reports/phase1-guile-local-build-validation.md`
+
+Important findings:
+
+- the local Guile executable initially still crashed until it was forced to load its matching local `libguile-3.0.so.1`
+- once `LD_LIBRARY_PATH` pointed at the local install lib directory, subprocess helpers worked correctly
+- this strongly supports the earlier diagnosis and shows that the upstream Guile fix resolves the problem in practice
+- the local `~/repos/bdwgc` checkout was not needed for this step; packaged `boehm-gc-threaded` was sufficient so far
+
+Current assessment:
+
+- Phase 1.1 now has both a root-cause analysis and a working validated fix path on amd64
+- no source changes were needed in `~/repos/guile` because the local checkout already contains the relevant upstream fix
+- no source changes were needed in `~/repos/bdwgc` yet, but the earlier FreeBSD warning keeps it on the watch list
+- the project can now move on to Phase 1.2 with a known-good local Guile fallback
+
 Recent commits:
 
 - `e380e88` — `Add FreeBSD Guile verification harness`
 - `cd721b1` — `Update progress after Guile verification`
+- `27916cb` — `Diagnose Guile subprocess crash on FreeBSD`
 
 Next recommended step:
 
-1. patch or locally validate a fix for the `addclosefrom_np` / `REPLACE_POSIX_SPAWN` mismatch
+1. begin Phase 1.2 by creating a minimal native FreeBSD build environment exercise (for example, GNU Hello or an even smaller autotools package)
-2. re-run both Guile test harnesses after the fix
+2. use the local fixed Guile build when subprocess helpers are required
-3. once subprocess behavior is stable, continue with Phase 1.2 (minimal native build environment / GNU Hello)
+3. keep `bdwgc` in reserve if later FreeBSD-specific GC/thread issues appear

docs/reports/phase1-guile-local-build-validation.md

@@ -0,0 +1,171 @@
+# Phase 1.1 follow-up: local Guile build validates the FreeBSD subprocess fix
+
+Date: 2026-04-01
+
+## Summary
+
+A local build of `~/repos/guile` was used to validate the previously identified FreeBSD subprocess crash.
+
+Result:
+
+- the packaged FreeBSD Guile (`/usr/local/bin/guile3`) still reproduces the crash
+- a locally built Guile from `~/repos/guile` works correctly for:
+  - `system*`
+  - `spawn`
+  - `open-pipe*`
+- no local source patch to `~/repos/guile` was required because the local checkout already contains the upstream fix commit
+
+The relevant upstream commit already present in `~/repos/guile` is:
+
+- `eb828801f621d3e130b6fe88cfc4acaa69b98a03`
+- subject: `Don't use posix_spawn_file_actions_addclosefrom_np with glib posix_spawn`
+
+The tested local checkout revision was:
+
+- `bbf2baa10f6cc8dfdd9e4ea14b503d748287a03d`
+
+## Additional build tooling installed on FreeBSD
+
+To build Guile from the local checkout, these packages were installed:
+
+```sh
+sudo pkg install -y autoconf automake libtool gettext-tools texinfo help2man gperf pkgconf
+```
+
+An extra FreeBSD-specific detail also mattered:
+
+- Guile's `autogen.sh` expects GNU `m4`
+- FreeBSD base `/usr/bin/m4` is not GNU `m4`
+- the installed GNU version is available as `gm4`
+- `autogen.sh` therefore had to be run with `M4=gm4`
+
+## Build procedure used
+
+A disposable build copy was created from the local repo to avoid polluting `~/repos/guile`:
+
+```sh
+git clone --shared ~/repos/guile /tmp/guile-freebsd-validate-src
+```
+
+Autotools bootstrap:
+
+```sh
+cd /tmp/guile-freebsd-validate-src
+M4=gm4 ./autogen.sh
+```
+
+Configure:
+
+```sh
+cd /tmp/guile-freebsd-validate-build
+env \
+  M4=gm4 \
+  MAKE=gmake \
+  PKG_CONFIG=pkg-config \
+  PKG_CONFIG_PATH=/usr/local/libdata/pkgconfig:/usr/local/lib/pkgconfig \
+  CPPFLAGS='-I/usr/local/include' \
+  LDFLAGS='-L/usr/local/lib -Wl,-rpath,/usr/local/lib' \
+  /tmp/guile-freebsd-validate-src/configure \
+    --prefix=/tmp/guile-freebsd-validate-install \
+    --with-bdw-gc=bdw-gc-threaded \
+    --with-libgmp-prefix=/usr/local \
+    --with-libunistring-prefix=/usr/local \
+    --with-libiconv-prefix=/usr/local \
+    --with-libintl-prefix=/usr/local
+```
+
+Build and install:
+
+```sh
+cd /tmp/guile-freebsd-validate-build
+gmake -j4
+gmake install
+```
+
+## Important validation detail: the executable must load the matching local libguile
+
+Immediately after installation, running `/tmp/guile-freebsd-validate-install/bin/guile` without adjusting the dynamic linker path still loaded the system `libguile-3.0.so.1` from `/usr/local/lib`, so it still crashed.
+
+This was confirmed with:
+
+```sh
+ldd /tmp/guile-freebsd-validate-install/bin/guile
+```
+
+To test the local build correctly, the process must use:
+
+```sh
+LD_LIBRARY_PATH=/tmp/guile-freebsd-validate-install/lib
+```
+
+The project test harnesses were updated accordingly so that when `GUILE_BIN` points to a non-system installation, the sibling `../lib` directory is automatically prepended to `LD_LIBRARY_PATH`.
+
+## Validation results
+
+### 1. Packaged Guile still reproduces the problem
+
+```sh
+./tests/guile/run-subprocess-diagnostics.sh
+```
+
+Observed result:
+
+- `system*` exits `139`
+- `spawn` exits `139`
+- `open-pipe*` exits `139`
+
+### 2. Local Guile succeeds when using the matching local libguile
+
+```sh
+EXPECT_GUILE_SUBPROCESS_CRASH=0 \
+GUILE_BIN=/tmp/guile-freebsd-validate-install/bin/guile \
+./tests/guile/run-subprocess-diagnostics.sh
+```
+
+Observed result:
+
+```text
+system-star exit=0
+spawn exit=0
+open-pipe-star exit=0
+Guile subprocess helpers succeeded as expected
+```
+
+### 3. The broader Phase 1.1 verification suite also passes with the local build
+
+```sh
+GUILE_BIN=/tmp/guile-freebsd-validate-install/bin/guile \
+./tests/guile/run-phase1-verification.sh
+```
+
+Observed result:
+
+- module loading: pass
+- deterministic output: pass
+- file I/O: pass
+- process fork/wait: pass
+- loopback sockets: pass
+- FFI: pass
+- `(guix build make-bootstrap)` import and `copy-linux-headers`: pass
+
+## boehm-gc note
+
+The user noted a package warning that Boehm GC is unmaintained on FreeBSD. For this specific validation step:
+
+- the local `~/repos/bdwgc` checkout was not needed
+- the packaged `boehm-gc-threaded` installation was sufficient to build and run the fixed local Guile
+- no local bdwgc source patch was necessary yet
+
+That said, the warning is worth keeping in mind as a likely future brittleness point if later Guile or Guix behavior exposes GC- or thread-related FreeBSD issues.
+
+## Conclusion
+
+The local build validates the earlier root-cause analysis in practice:
+
+- the packaged Guile is broken on FreeBSD for subprocess helpers
+- a newer local Guile checkout that already contains upstream commit `eb828801f...` no longer crashes
+- the next Guix-on-FreeBSD work can proceed using either:
+  1. a locally built fixed Guile, or
+  2. a backported packaging patch carrying the same upstream fix
+
+This clears the way to proceed into Phase 1.2 while keeping a documented workaround available on the current host.

tests/guile/run-phase1-verification.sh

@@ -10,15 +10,32 @@ if [ ! -d "$guix_source_dir/guix" ]; then
   exit 1
 fi
 
-if command -v guile3 >/dev/null 2>&1; then
+if [ -n "${GUILE_BIN:-}" ]; then
+  guile_bin=$GUILE_BIN
+elif command -v guile3 >/dev/null 2>&1; then
   guile_bin=$(command -v guile3)
 elif command -v guile-3.0 >/dev/null 2>&1; then
   guile_bin=$(command -v guile-3.0)
 else
-  echo "Unable to find guile3 or guile-3.0 in PATH" >&2
+  echo "Unable to find GUILE_BIN, guile3, or guile-3.0 in PATH" >&2
   exit 1
 fi
 
+if [ ! -x "$guile_bin" ]; then
+  echo "Guile binary is not executable: $guile_bin" >&2
+  exit 1
+fi
+
+guile_prefix=$(CDPATH= cd -- "$(dirname "$guile_bin")/.." && pwd)
+guile_lib_dir=$guile_prefix/lib
+if [ -e "$guile_lib_dir/libguile-3.0.so.1" ]; then
+  if [ -n "${LD_LIBRARY_PATH:-}" ]; then
+    export LD_LIBRARY_PATH="$guile_lib_dir:$LD_LIBRARY_PATH"
+  else
+    export LD_LIBRARY_PATH="$guile_lib_dir"
+  fi
+fi
+
 export GUIX_SOURCE_DIR="$guix_source_dir"
 export GUILE_AUTO_COMPILE=${GUILE_AUTO_COMPILE:-0}
 if [ -n "${GUILE_LOAD_PATH:-}" ]; then
@@ -27,4 +44,6 @@ else
   export GUILE_LOAD_PATH="$repo_root/tests/guile/modules:$guix_source_dir"
 fi
 
+echo "Using Guile: $guile_bin" >&2
+echo "Using LD_LIBRARY_PATH: ${LD_LIBRARY_PATH:-<unset>}" >&2
 exec "$guile_bin" -s "$repo_root/tests/guile/verify-phase1.scm" "$@"

tests/guile/run-subprocess-diagnostics.sh

@@ -6,23 +6,44 @@ repo_root=$(CDPATH= cd -- "$script_dir/../.." && pwd)
 workdir=$(mktemp -d /tmp/fruix-guile-subprocess.XXXXXX)
 trap 'rm -rf "$workdir"' EXIT INT TERM
 
-if command -v guile3 >/dev/null 2>&1; then
+if [ -n "${GUILE_BIN:-}" ]; then
+  guile_bin=$GUILE_BIN
+elif command -v guile3 >/dev/null 2>&1; then
   guile_bin=$(command -v guile3)
 elif command -v guile-3.0 >/dev/null 2>&1; then
   guile_bin=$(command -v guile-3.0)
 else
-  echo "Unable to find guile3 or guile-3.0 in PATH" >&2
+  echo "Unable to find GUILE_BIN, guile3, or guile-3.0 in PATH" >&2
   exit 1
 fi
 
+if [ ! -x "$guile_bin" ]; then
+  echo "Guile binary is not executable: $guile_bin" >&2
+  exit 1
+fi
+
+guile_prefix=$(CDPATH= cd -- "$(dirname "$guile_bin")/.." && pwd)
+guile_lib_dir=$guile_prefix/lib
+if [ -e "$guile_lib_dir/libguile-3.0.so.1" ]; then
+  if [ -n "${LD_LIBRARY_PATH:-}" ]; then
+    export LD_LIBRARY_PATH="$guile_lib_dir:$LD_LIBRARY_PATH"
+  else
+    export LD_LIBRARY_PATH="$guile_lib_dir"
+  fi
+fi
+
 ulimit -c 0 || true
 
 cc -Wall -Wextra -O2 "$repo_root/tests/guile/posix-spawn-freebsd-diagnostics.c" \
   -o "$workdir/posix-spawn-freebsd-diagnostics"
 
+printf 'Using Guile: %s\n' "$guile_bin"
+printf 'Using LD_LIBRARY_PATH: %s\n' "${LD_LIBRARY_PATH:-<unset>}"
 printf '== Native posix_spawn diagnostics ==\n'
 "$workdir/posix-spawn-freebsd-diagnostics"
 
+expect_crash=${EXPECT_GUILE_SUBPROCESS_CRASH:-1}
+
 run_guile_case() {
   name=$1
   code=$2
@@ -31,12 +52,24 @@ run_guile_case() {
   rc=$?
   set -e
   printf '%s exit=%s\n' "$name" "$rc"
+  if [ "$expect_crash" -eq 1 ]; then
     [ "$rc" -eq 139 ]
+  else
+    [ "$rc" -eq 0 ]
+  fi
 }
 
-printf '== Guile subprocess crash repro ==\n'
+if [ "$expect_crash" -eq 1 ]; then
+  printf '== Guile subprocess crash repro ==\n'
+else
+  printf '== Guile subprocess validation (expect success) ==\n'
+fi
 run_guile_case system-star '(system* "/usr/bin/true")'
 run_guile_case spawn '(spawn "/usr/bin/true" (list "/usr/bin/true"))'
 run_guile_case open-pipe-star '(use-modules (ice-9 popen)) (open-pipe* OPEN_READ "/usr/bin/true")'
 
-printf 'known FreeBSD Guile subprocess crash profile reproduced\n'
+if [ "$expect_crash" -eq 1 ]; then
+  printf 'known FreeBSD Guile subprocess crash profile reproduced\n'
+else
+  printf 'Guile subprocess helpers succeeded as expected\n'
+fi