---
id: "bug-1910"
status: "fixed"
status_updated: "2026-10-03"
status_note: ""
component: "tooling"
severity: "wrong-result"
timestamp: "2026-10-03T12:14:03Z"
last_seen: "2026-10-03T12:14:03Z"
occurrences: 1
files: ["src/tools/test-version-startup-consistency.sh", "src/tools/test-dirty-fingerprint-startup-log-unchanged.sh"]
tags: ["test-script", "apiserver", "go", "vendor"]
related: ["bug-1607", "bug-1608", "bug-1909"]
fix_commits: ["ef6e562c"]
---

# bug-1910: version scripts' apiserver go build uses -mod=readonly and fails without a Go module cache

## Description
**Observed:**
```
models/auth.go:4:2: module lookup disabled by GOPROXY=off
utils/utils.go:18:2: module lookup disabled by GOPROXY=off
...
FATAL: command failed (line 383)
```
Both `test-version-startup-consistency.sh` and `test-dirty-fingerprint-startup-log-unchanged.sh` build the apiserver with `GOPROXY=off go build -mod=readonly ...`. `-mod=readonly` makes Go ignore the committed `src/frontend/apiserver/vendor/` tree and resolve modules from the module cache, which this machine does not have, so the build fails and the scripts never reach their apiserver checks.

**Expected:** the scripts build the apiserver the way the canonical meson build does (`GOFLAGS=-mod=vendor`, `src/frontend/apiserver/meson.build:89`), which needs no module cache and never modifies go.mod/go.sum (the concern -mod=readonly was added for, bug-1607).
**Impact:** both scripts exit 1 on any machine without a populated Go module cache; their apiserver halves are never exercised. Test-only.
**Found by:** spec task (controller-peers-env-fallback tasks 5.2/5.3)

## Environment
- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
- libc: glibc 2.42-47 (nix devShell, /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47)
- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
- Build: debug (the scripts' own lib/scheduler builds) + direct `go build` of the apiserver
- Code: scheduler-framework @ 66520e6b-dirty
- Deployment: n/a — local script builds, no cluster

## Reproduction
1. On a machine with no Go module cache, run `bash src/tools/test-dirty-fingerprint-startup-log-unchanged.sh` (or `test-version-startup-consistency.sh`).
2. The apiserver step fails with `module lookup disabled by GOPROXY=off`.
- Frequency: deterministic on this machine, 2026-10-03 (every run during controller-peers-env-fallback 5.2/5.3)
- Evidence: not kept (scratchpad logs from the 5.3 run)

## Root cause
Both scripts build the apiserver with `GOPROXY=off go build -mod=readonly`. `-mod=readonly` makes Go ignore the committed `src/frontend/apiserver/vendor/` tree and resolve modules from the module cache; the scripts were written on a machine whose cache was already populated, so on a machine without one every import fails with `module lookup disabled by GOPROXY=off`.

## Fix
Use `-mod=vendor`, as the canonical meson build does (`GOFLAGS=-mod=vendor`, `src/frontend/apiserver/meson.build:89`). Vendor mode needs no module cache and never modifies go.mod/go.sum, so the bug-1607 no-repo-mutation property still holds. Header comments updated in both scripts.

## Verification
- Test: `bash src/tools/test-dirty-fingerprint-startup-log-unchanged.sh` — RED before (FATAL at the apiserver `go build`, 12x `module lookup disabled by GOPROXY=off`), GREEN after (exit 0, apiserver checks PASS); same for `test-version-startup-consistency.sh` (exit 0, `PASS [apiserver]`), 2026-10-03.
- Suites: go.mod/go.sum unchanged (md5 and `git status src/frontend` checked by the reviewer); `xce-build.sh all --incremental` (asan) green.
- Live: n/a (test-script defect)

## References
- Related: none