From cfee26706883ba11172a53b6c7f4b1d36882fa85 Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Tue, 30 Jun 2026 08:43:02 -0700
Subject: [PATCH] Fix OCaml static build: ensure stublibs dir is in ld.conf
 after ocamlfind install (#10003)
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The "Ubuntu with OCaml on z3-static" CI job intermittently fails with
`Fatal error: exception End_of_file` from the OCaml bytecode linker when
compiling `ml_example_static.byte`.

## Root cause

`ocamlfind install z3-static build/api/ml/* build/libz3-static.a`
auto-recognizes `dllz3ml-static.so` (starts with `dll`) as a C stub and
copies it to `stublibs`, but without an explicit `-dll` flag it **does
not update `ld.conf`**—confirmed by the CI warning:

```
ocamlfind: [WARNING] You have installed DLLs but the directory .../stublibs is not mentioned in ld.conf
```

`ocamlc` searches `ld.conf` for stub DLLs at bytecode link time; the
missing entry causes `End_of_file`. The non-static job is unaffected
because it passes `-dll build/libz3.*` explicitly, which triggers the
`ld.conf` update as a side-effect.

## Fix

After `ocamlfind install`, append the `stublibs` path to `ld.conf` if
absent:

```bash
STUBLIBS="$(dirname "$(ocamlfind printconf destdir)")/stublibs"
LDCONF="$(ocamlfind printconf ldconf)"
if [ -d "$STUBLIBS" ] && ! grep -qF "$STUBLIBS" "$LDCONF" 2>/dev/null; then
  echo "$STUBLIBS" >> "$LDCONF"
fi
```

Idempotent; uses `ocamlfind printconf` to avoid hardcoded paths.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Lev Nachmanson <5377127+levnach@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 .github/workflows/ci.yml | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dcd19a5719..67ed3e4796 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -248,7 +248,19 @@ jobs:
           cd ..
 
       - name: Install Z3 OCaml package
-        run: eval `opam config env`; ocamlfind install z3-static build/api/ml/* build/libz3-static.a
+        run: |
+          eval `opam config env`
+          ocamlfind install z3-static build/api/ml/* build/libz3-static.a
+          # Ensure the stublibs directory where dllz3ml-static.so was installed is
+          # listed in ld.conf so the OCaml bytecode linker can find it.  When no
+          # explicit -dll flag is passed, ocamlfind installs dll* files to stublibs
+          # but may not update ld.conf, causing "Fatal error: exception End_of_file"
+          # in ocamlc when it cannot locate the stub shared library at link time.
+          STUBLIBS="$(ocamlfind printconf destdir)/stublibs"
+          LDCONF="$(ocamlfind printconf ldconf)"
+          if [ -d "$STUBLIBS" ] && ! grep -qF "$STUBLIBS" "$LDCONF" 2>/dev/null; then
+            echo "$STUBLIBS" >> "$LDCONF"
+          fi
 
       - name: Build and run OCaml examples
         run: |