fix: one-shot-token.so fails to load on musl/Alpine hosts (ARC runners) by Copilot · Pull Request #2538 · github/gh-aw-firewall

Copilot · 2026-05-05T03:56:30Z

one-shot-token.so compiled against glibc pulls in __fprintf_chk (a _FORTIFY_SOURCE artifact), causing LD_PRELOAD to fail with symbol not found: __fprintf_chk on musl-based hosts (Alpine DinD / ARC self-hosted runners).

Changes

Dockerfile + build.sh: Add -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0 to gcc flags — eliminates the __fprintf_chk dependency while preserving all other hardening:

gcc -shared -fPIC -fvisibility=hidden -O2 -Wall -s \
    -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0 \
    -o /usr/local/lib/one-shot-token.so one-shot-token.c -ldl -lpthread

entrypoint.sh (chroot mode): Add a runtime compatibility probe before setting ONE_SHOT_TOKEN_LIB. Uses the host's own /bin/true to surface linker failures before committing to LD_PRELOAD; degrades gracefully with a warning rather than crashing on incompatible hosts:

if LD_PRELOAD=/host/tmp/awf-lib/one-shot-token.so /host/bin/true 2>/dev/null; then
    ONE_SHOT_TOKEN_LIB="/tmp/awf-lib/one-shot-token.so"
else
    echo "[entrypoint][WARN] one-shot-token.so failed to load on host libc (e.g. musl/Alpine)"
    # token protection disabled, tokens remain in env
fi

README.md: Update build snippet and limitations to reflect musl compatibility and graceful degradation.

…ine hosts The one-shot-token.so LD_PRELOAD library was compiled against glibc with _FORTIFY_SOURCE enabled, causing __fprintf_chk to be linked in. On musl-based hosts (Alpine Linux / ARC self-hosted runners) this caused: Error relocating /tmp/awf-lib/one-shot-token.so: __fprintf_chk: symbol not found Changes: - Dockerfile: add -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0 to gcc flags - build.sh: same flags for local builds - entrypoint.sh: add runtime compatibility probe (chroot mode) using /host/bin/true before committing to LD_PRELOAD; graceful degradation with a warning if the .so fails to load on the host libc - README.md: document the fix and update limitations section Agent-Logs-Url: https://github.com/github/gh-aw-firewall/sessions/2f8a6925-e4bb-4c25-a59c-f4734dadfba2 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

github-actions · 2026-05-05T04:01:04Z

✅ Coverage Check Passed

Overall Coverage

Metric	Base	PR	Delta
Lines	86.45%	86.53%	📈 +0.08%
Statements	86.38%	86.46%	📈 +0.08%
Functions	90.61%	90.61%	➡️ +0.00%
Branches	79.23%	79.27%	📈 +0.04%

📁 Per-file Coverage Changes (1 files)

File	Lines (Before → After)	Statements (Before → After)
`src/container-lifecycle.ts`	86.1% → 87.2% (+1.09%)	86.3% → 87.4% (+1.08%)

Coverage comparison generated by scripts/ci/compare-coverage.ts

Copilot

Pull request overview

This PR aims to improve reliability of the agent’s one-shot-token.so LD_PRELOAD library when running in chroot mode on musl/Alpine-based hosts (e.g., ARC runners), by adjusting compilation flags to avoid fortified glibc symbol dependencies and adding a runtime compatibility probe with graceful fallback.

Changes:

Add -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0 to the one-shot-token.so build in the agent Dockerfile and the local build.sh.
Add a runtime probe in containers/agent/entrypoint.sh to avoid enabling LD_PRELOAD when the host loader/libc can’t load the library.
Update one-shot-token README to document the build flag rationale and chroot limitations.

Show a summary per file

File	Description
containers/agent/one-shot-token/README.md	Documents the new build flags and updates limitations language for musl/glibc behavior.
containers/agent/one-shot-token/build.sh	Adds the same compile flags for local builds (but currently has a blocking script issue).
containers/agent/entrypoint.sh	Adds a host compatibility probe before setting LD_PRELOAD in chroot mode.
containers/agent/Dockerfile	Adds the compile flags during image build to reduce glibc fortified-symbol linkage.

Copilot's findings

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Files reviewed: 4/4 changed files
Comments generated: 3

+        # Probe compatibility with the host's dynamic linker before committing to LD_PRELOAD.
+        # The .so is compiled against glibc; on musl-based hosts (Alpine/ARC runners) it will
+        # fail to load with "symbol not found: __fprintf_chk".  Running the host's /bin/true
+        # (which uses the host's own libc) surfaces this error without breaking anything.
+        if LD_PRELOAD=/host/tmp/awf-lib/one-shot-token.so /host/bin/true 2>/dev/null; then
+          ONE_SHOT_TOKEN_LIB="/tmp/awf-lib/one-shot-token.so"
+          echo "[entrypoint] One-shot token library copied to chroot at ${ONE_SHOT_TOKEN_LIB}"
+        else
+          echo "[entrypoint][WARN] one-shot-token.so failed to load on host libc (e.g. musl/Alpine)"


+# -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0: disable glibc fortification macros
+#   (e.g. __fprintf_chk) so the .so loads on musl-based hosts (Alpine/ARC runners)
 gcc -shared -fPIC \
    -fvisibility=hidden \
    -O2 -Wall -Wextra -s \
+    -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0 \
    -o "${OUTPUT_FILE}" \
    "${SOURCE_FILE}" \


Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

lpcox · 2026-05-05T04:40:52Z

@copilot address the review feedback

- entrypoint.sh: run LD_PRELOAD compatibility probe inside chroot /host so the ELF interpreter resolves against the host filesystem (avoids false negatives on glibc containers with musl hosts) - entrypoint.sh: broaden warning message to reflect general linker incompatibility rather than only __fprintf_chk - build.sh: define SOURCE_FILE and OUTPUT_FILE variables (were referenced but never defined, causing local builds to fail) - build.sh: fix stale comment claiming Rust/Cargo build Agent-Logs-Url: https://github.com/github/gh-aw-firewall/sessions/74ad4f01-8832-4d73-b9bc-ee83a6ad7882 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot · 2026-05-05T04:42:33Z

@copilot address the review feedback

Done in 4114e61. Three issues addressed:

entrypoint.sh probe: Changed from LD_PRELOAD=/host/tmp/... /host/bin/true to chroot /host /bin/sh -c 'LD_PRELOAD=/tmp/awf-lib/one-shot-token.so /bin/true' — the probe now runs inside the chroot so the ELF interpreter (e.g. /lib/ld-musl-*.so.1 on Alpine) resolves against the host filesystem, not the container's. Also broadened the warning message to reflect general linker incompatibility rather than __fprintf_chk specifically.
build.sh variables: Added SOURCE_FILE="${SCRIPT_DIR}/one-shot-token.c" and OUTPUT_FILE="${SCRIPT_DIR}/one-shot-token.so" definitions (they were used throughout the script but never defined). Also fixed the stale "Rust/Cargo" comment.

github-actions · 2026-05-05T04:46:44Z

🔬 Smoke Test Results

Test	Status
GitHub MCP connectivity	✅
GitHub.com HTTP connectivity	✅ (pre-step)
File write/read	⚠️ path not expanded (template vars unresolved)

PR: fix: one-shot-token.so fails to load on musl/Alpine hosts (ARC runners)
Author: @Copilot | Assignees: @lpcox @Copilot

Overall: PASS (MCP and HTTP confirmed; file test skipped due to unexpanded template vars)

📰 BREAKING: Report filed by Smoke Copilot

github-actions · 2026-05-05T04:47:08Z

Smoke Test Results

✅ GitHub MCP: Last 2 merged PRs retrieved
✅ Playwright: Page navigation + title verification
✅ File Writing: Test file created with timestamp
✅ Bash: File content verified

Status: PASS

💥 [THE END] — Illustrated by Smoke Claude

github-actions · 2026-05-05T04:47:56Z

Chroot Version Comparison Results

Runtime	Host Version	Chroot Version	Match?
Python	Python 3.12.13	Python 3.12.3	❌ NO
Node.js	v24.14.1	v20.20.2	❌ NO
Go	go1.22.12	go1.22.12	✅ YES

Result: ❌ Not all tests passed. Python and Node.js versions differ between host and chroot environments. The smoke-chroot label was not applied.

Tested by Smoke Chroot

github-actions · 2026-05-05T04:48:06Z

Smoke Test: Copilot BYOK (Offline) Mode

Test	Result
GitHub MCP (`fix: unexport internal helpers from ssl-bump and host-iptables`)	✅
GitHub.com connectivity	⚠️ pre-step data unavailable (template not substituted)
File write/read	⚠️ pre-step data unavailable (template not substituted)
BYOK inference (agent → api-proxy → api.githubcopilot.com)	✅

Running in BYOK offline mode (COPILOT_OFFLINE=true) via api-proxy → api.githubcopilot.com

PR by @Copilot, assignees: @lpcox, @Copilot

Overall: PARTIAL PASS (BYOK inference ✅; pre-step outputs not substituted)

🔑 BYOK report filed by Smoke Copilot BYOK

github-actions · 2026-05-05T04:48:38Z

Smoke Test

fix: unexport internal helpers from ssl-bump and host-iptables (#2532)
api-proxy: listen on all ports unconditionally, return clear errors for missing credentials (#2520)
GitHub MCP review ❌
Safeinputs GH CLI query ❌
Playwright title check ✅
Tavily search ❌
File write/read + bash verify ✅
Discussion comment ✅
Build (npm ci && npm run build) ✅
Overall status: FAIL

Warning

Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

registry.npmjs.org

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "registry.npmjs.org"

See Network Configuration for more information.

🔮 The oracle has spoken through Smoke Codex

github-actions · 2026-05-05T04:48:48Z

Smoke Test Results

Redis PING: ❌ (connection timeout)
PostgreSQL pg_isready: ❌ (no response on port 5432)
PostgreSQL SELECT 1: ❌ (not attempted, pg_isready failed)

Overall: FAIL — host.docker.internal is not reachable from this environment. Service containers appear unavailable.

🔌 Service connectivity validated by Smoke Services

github-actions · 2026-05-05T04:49:15Z

🏗️ Build Test Suite Results

Ecosystem	Project	Build/Install	Tests	Status
Bun	elysia	✅	1/1 passed	✅ PASS
Bun	hono	✅	1/1 passed	✅ PASS
C++	fmt	✅	N/A	✅ PASS
C++	json	✅	N/A	✅ PASS
Deno	oak	N/A	1/1 passed	✅ PASS
Deno	std	N/A	1/1 passed	✅ PASS
.NET	hello-world	✅	N/A	✅ PASS
.NET	json-parse	✅	N/A	✅ PASS
Go	color	✅	1/1 passed	✅ PASS
Go	env	✅	1/1 passed	✅ PASS
Go	uuid	✅	1/1 passed	✅ PASS
Java	gson	✅	1/1 passed	✅ PASS
Java	caffeine	✅	1/1 passed	✅ PASS
Node.js	clsx	✅	All passed	✅ PASS
Node.js	execa	✅	All passed	✅ PASS
Node.js	p-limit	✅	All passed	✅ PASS
Rust	fd	✅	1/1 passed	✅ PASS
Rust	zoxide	✅	1/1 passed	✅ PASS

Overall: 8/8 ecosystems passed — ✅ PASS

Generated by Build Test Suite for issue #2538 · ● 588.3K · ◷

Initial plan

972970b

Copilot AI assigned Copilot and lpcox May 5, 2026

Copilot started work on behalf of lpcox May 5, 2026 03:56 View session

Copilot AI linked an issue May 5, 2026 that may be closed by this pull request

one-shot-token.so LD_PRELOAD fails on musl/Alpine hosts (ARC self-hosted runners) #2535

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lpcox marked this pull request as ready for review May 5, 2026 03:59

lpcox requested a review from Mossaka as a code owner May 5, 2026 03:59

Copilot AI review requested due to automatic review settings May 5, 2026 03:59

Copilot AI changed the title ~~[WIP] Fix one-shot-token.so LD_PRELOAD loading issue on Alpine hosts~~ fix: one-shot-token.so fails to load on musl/Alpine hosts (ARC runners) May 5, 2026

Copilot finished work on behalf of lpcox May 5, 2026 04:00

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[aw] No-Op Runs #2301

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Potential fix for pull request finding

92a9425

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot started work on behalf of lpcox May 5, 2026 04:41 View session

Copilot finished work on behalf of lpcox May 5, 2026 04:42

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