From 47ca07ef4e93624fb839b639f064f20aae910851 Mon Sep 17 00:00:00 2001
From: Yusuke Watanabe <42527473+ywatanabe1989@users.noreply.github.com>
Date: Fri, 24 Jul 2026 02:20:40 +0900
Subject: [PATCH] =?UTF-8?q?fix(ci):=20remove=20the=20per-runner=20RUNNER?=
 =?UTF-8?q?=5FTOOL=5FCACHE=20env=20=E2=80=94=20it=20is=20a=20no-op?=
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The step-level env added in the previous change does NOT take effect:
RUNNER_TOOL_CACHE is a runner-reserved default variable, and a workflow-level
env does not override it. Measured on scitex-hpc ci run 30028631599
(2026-07-23, after the previous merge): all pytest-matrix legs still resolved
the runner's ~/.runner-toolcache, not the intended per-runner /tmp path,
identical to the unpatched jobs.

Leaving a no-op that looks like a fix is worse than no fix. Replaced with a
comment recording the finding and pointing at the only layer that can fix the
shared-toolcache flake: the runner launcher (relaunch-scitex-hpc-runner.sh),
which is where RUNNER_TOOL_CACHE is exported. Tracked in scitex-hpc card
ci-runner-toolcache-per-runner-launcher-ssot-20260723.
---
 .github/workflows/pytest-matrix.yml | 45 ++++++-----------------------
 1 file changed, 9 insertions(+), 36 deletions(-)

diff --git a/.github/workflows/pytest-matrix.yml b/.github/workflows/pytest-matrix.yml
index e21e05b..6cf38cb 100644
--- a/.github/workflows/pytest-matrix.yml
+++ b/.github/workflows/pytest-matrix.yml
@@ -36,42 +36,15 @@ jobs:
       - uses: astral-sh/setup-uv@v7
         with:
           cache-dependency-glob: pyproject.toml
-        env:
-          # PER-RUNNER TOOL CACHE. Every runner on the Spartan lease inherited
-          # RUNNER_TOOL_CACHE=~/.runner-toolcache from the supervisor, so ~80
-          # runners shared ONE mutable cache on GPFS. @actions/tool-cache's
-          # writer is destructive, not additive:
-          #
-          #   _createToolPath():  rmRF(<ver>/<arch>)      <- deletes the tree
-          #                       rmRF(<ver>/<arch>.complete)
-          #                       mkdirP(<ver>/<arch>)
-          #   ...copy files in...
-          #   _completeToolPath(): write <arch>.complete
-          #
-          # and the reader, find(), treats dir + `.complete` as a HIT and puts
-          # it on PATH WITHOUT checking that the binary is inside. So when a new
-          # uv release makes every concurrent job a cache MISS at once, each one
-          # deletes the tree the others are using or filling. Two observed faces,
-          # same cause:
-          #   ENOENT copying into the toolcache  (two writers collide)
-          #   "Added .../uv/<ver>/x86_64 to the path" then
-          #   ".../uv: No such file or directory" -> exit 127
-          #     (a reader's hit gets deleted under it — figrecipe main, run
-          #      29945387939, 2026-07-22: all three matrix legs, three runners)
-          #
-          # Scoping the cache per runner removes the sharing, so no job can
-          # destroy another's tree. This is why PRE-SEEDING the image does NOT
-          # fix it: _createToolPath rmRF's a pre-seeded tree exactly the same.
-          #
-          # /tmp is node-local and may be cleared: that degrades to a cache MISS
-          # (re-download, slower), never a dangling path — mkdirP recreates it.
-          # Deliberately NOT on GPFS: punim0264 is at 98.2% of its 8M inode
-          # limit and a per-runner cache there would multiply inode use by ~80.
-          #
-          # Set at STEP level on purpose: the `runner` context is not available
-          # to job-level `env`. setup-uv writes the resolved path to $GITHUB_PATH,
-          # so later steps resolve uv without needing this variable themselves.
-          RUNNER_TOOL_CACHE: /tmp/scitex-ci-runner-work/toolcache/${{ runner.name }}
+        # NOTE: a per-runner RUNNER_TOOL_CACHE override was tried here and
+        # REMOVED as a no-op. RUNNER_TOOL_CACHE is a runner-reserved default;
+        # a workflow-level `env:` does NOT override it (measured 2026-07-23,
+        # scitex-hpc ci run 30028631599: the step still resolved the runner's
+        # ~/.runner-toolcache, not the override). The shared-toolcache flake
+        # (setup-uv concurrent-populate mutual destruction) can only be fixed
+        # where the RUNNER exports the variable — the launcher script
+        # (relaunch-scitex-hpc-runner.sh), per-runner + node-local. Tracked in
+        # scitex-hpc card ci-runner-toolcache-per-runner-launcher-ssot-20260723.
       - name: Install (.[all,dev]) + pytest
         run: |
           set -euo pipefail