docs: add B10 to runner doctor catalog (rootless perm-repair tag@digest timeout) (#6078)

* Initial plan

* docs: add B10 failure mode to runner doctor catalog

Add new failure mode B10 (rootless permission repair timeout on
tag@digest ref) to all three mirrored catalog files:

- .github/workflows/shared/self-hosted-failure-modes.md
- .github/workflows/self-hosted-runner-doctor.md
- .github/agents/self-hosted-runner-doctor.md

B10 captures the symptom from PR #6025: fixArtifactPermissionsForRootless()
built compound tag@digest refs that caused Docker to attempt GHCR
manifest verification even under --pull never, timing out ~30 s per
directory. Fixed by resolvePermFixerImageRef() returning tag-only refs.

Closes #6069

* Potential fix for pull request finding

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

* Potential fix for pull request finding

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

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Landon Cox <landon.cox@microsoft.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

.github/agents/self-hosted-runner-doctor.md

@@ -80,6 +80,7 @@ Prefer the narrowest match. Examples:
 - `EACCES: permission denied, mkdir '/tmp/gh-aw/...'` before containers start on a persistent runner → B8 (stale root-owned pre-flight dirs)
 - `FATAL: http_port: IPv6 is not available` → B3
 - `No CA certificates were loaded from the system` in chroot on RHEL/Fedora/Amazon Linux → B9 (missing /etc/pki/ mount)
+- `[WARN] Rootless artifact permission repair failed` with each attempt taking ~30 s (registry timeout, not instant) → B10 (compound tag@digest ref causes Docker to attempt GHCR manifest verification even under `--pull never`)
 - `none of the git remotes correspond to the GH_HOST environment variable` → C4
 - `400 bad request: Authorization header is badly formatted` → C3
 - `400 bad request: Authorization header is badly formatted` on `*.ghe.com` with `COPILOT_API_TARGET=api.business.githubcopilot.com` → C8 (platform-type guard short-circuits token-prefix catalog)
@@ -100,6 +101,8 @@ B8 / github/gh-aw-firewall#5983 — Pre-flight EACCES on persistent runners from
 
 B9 / github/gh-aw-firewall#5783 — RHEL/Amazon Linux CA bundle not accessible in chroot is **fixed** in AWF version including github/gh-aw-firewall#5783. Workaround: copy `/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` to a chroot-visible path and set `SSL_CERT_FILE`/`NODE_EXTRA_CA_CERTS`/`REQUESTS_CA_BUNDLE`/`CURL_CA_BUNDLE`/`GIT_SSL_CAINFO`.
 
+B10 / github/gh-aw-firewall#6025 — `fixArtifactPermissionsForRootless()` compound `tag@digest` ref timeout is **fixed** in AWF version including github/gh-aw-firewall#6025. `resolvePermFixerImageRef()` now returns tag-only refs, eliminating registry I/O during `--pull never` repair.
+
 C7 / #5615 — DIFC proxy enterprise-host awareness for `*.ghe.com` data-residency is not yet implemented in the companion projects; AWF ≥ v0.27.12 provides improved diagnostics (HTTP status + targeted hint) but the underlying cause remains unresolved.
 
 C8 / github/gh-aw-firewall#5872 — Copilot Business `token` prefix short-circuit on GHEC is **fixed** in AWF version including github/gh-aw-firewall#5872.
@@ -180,6 +183,7 @@ Establish these facts before matching a failure mode:
 | B7 | AWF < v0.27.13: unhandled `EACCES` stack trace shows `unlink ... /tmp/awf-<ts>-chroot-home/<path>` (e.g. `.aws/config`, cloud credentials). AWF ≥ v0.27.13: `removeWorkDirectories()` catches the error and emits `[WARN] Failed to remove chroot home directory after permission repair` instead of crashing | In rootless Docker mode the agent container runs with UID namespace remapping. Files created by the agent inside the `chroot-home` temp directory are owned by remapped UIDs. AWF's `removeWorkDirectories()` runs as the unprivileged host runner and `fs.rmSync` fails on these files. | **Partially fixed in AWF v0.27.13** (repair container with CHOWN/DAC_OVERRIDE/FOWNER capabilities); **further fix merged post-v0.27.15** (#5717): in rootless Docker the repair container's `chown` operates within the user namespace and may not change host-level ownership. The post-v0.27.15 fix adds `chmod -R a+rwX` so the host can delete the directory regardless of ownership. Non-fatal if unfixed — leaves an orphan `/tmp/awf-*-chroot-home` dir. **additional hardening** (github/gh-aw-firewall#5766): changes `chown && chmod` to `chown 2>/dev/null; chmod` so `chmod` always runs as a fallback even when `chown` fails within the rootless UID namespace. | `ls -la /tmp/awf-*-chroot-home/` after a rootless run — files owned by non-runner UIDs confirm the mode; upgrade to AWF ≥ v0.27.13; check AWF logs for `[WARN] Failed to remove chroot home directory after permission repair` | #5653, github/gh-aw-firewall#5708, github/gh-aw-firewall#5717, github/gh-aw-firewall#5766 |
 | B8 | `EACCES: permission denied, mkdir '/tmp/gh-aw/sandbox/firewall/logs'` (or any `/tmp/gh-aw/...` path) — failure occurs **before any container starts**, at `writeConfigs` time, on a **persistent self-hosted runner** | A previous AWF run or the Docker daemon left `/tmp/gh-aw/sandbox/firewall/` (or a parent) owned by **root**. With `--network-isolation` now the default, AWF runs without `sudo`, so `mkdirSync` on the root-owned parent fails with EACCES. | **Fixed in AWF (PR github/gh-aw-firewall#5983)**: added `preflight-reclaim.ts` — on non-root invocation, walks upward from the target path to find the first non-writable ancestor and removes it via `sudo rm -rf` with `fs.rmSync` fallback; protected paths (`/`, `/tmp`, `/home/runner`) are never touched. Workaround (older AWF): `sudo rm -rf /tmp/gh-aw/sandbox` before re-running. | `ls -la /tmp/gh-aw/sandbox/firewall/` — dirs owned by root (uid 0) confirm the mode; `docker info | grep -i rootless` | github/gh-aw-firewall#5983 |
 | B9 | `No CA certificates were loaded from the system` — Copilot CLI or other HTTPS tools fail inside AWF chroot on RHEL, Fedora, or Amazon Linux runners; all HTTPS traffic returns TLS verification errors | AWF chroot mounts only Debian/Ubuntu CA paths (`/etc/ssl:ro`, `/etc/ca-certificates:ro`). On RHEL/Amazon Linux the system CA bundle lives under `/etc/pki/ca-trust/` which is not mounted. | **Fixed in AWF (PR github/gh-aw-firewall#5783)**: `copy_system_ca_bundle()` in agent entrypoint detects the CA bundle from 5 candidate paths (Debian, RHEL, Fedora, macOS, Alpine), copies it to `/tmp/awf-lib/system-ca-certificates.crt` if not directly accessible, and sets `SSL_CERT_FILE`, `NODE_EXTRA_CA_CERTS`, `REQUESTS_CA_BUNDLE`, `CURL_CA_BUNDLE`, `GIT_SSL_CAINFO`. Workaround: copy `/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` to a chroot-visible path and set those env vars. | `ls /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` — present on RHEL/Amazon Linux confirms the mode | github/gh-aw-firewall#5733, github/gh-aw-firewall#5783 |
+| B10 | `[WARN] Rootless artifact permission repair failed for .../sandbox/firewall/logs (exit 1)` × 3 directories, each taking exactly ~30 s; total ~90 s wasted; cascading `EACCES: permission denied` / `Failed to remove chroot home directory after permission repair` | `fixArtifactPermissionsForRootless()` builds compound `tag@digest` image refs (e.g. `agent:0.27.22@sha256:55f065...`) for its `docker run --pull never` repair container. Despite `--pull never`, Docker still attempts registry manifest verification for compound refs; when GHCR credentials are unavailable (cleaned in an earlier workflow step or expired) the verification TCP-connects and times out (~30 s per directory). | **Fixed in AWF (PR github/gh-aw-firewall#6025)**: `resolvePermFixerImageRef()` now strips the `@sha256:...` digest and uses a tag-only ref. `--pull never` with a tag-only ref skips all registry I/O. Upgrade to AWF version that includes github/gh-aw-firewall#6025. Workaround (older AWF): ensure GHCR credentials are available until after the AWF cleanup step. | `[WARN] Rootless artifact permission repair failed` messages each followed by exactly ~30 s delay in the workflow log; `docker pull --dry-run agent:...@sha256:...` times out while `docker inspect agent:...` succeeds | github/gh-aw-firewall#6025 |
 
 ## Category C — GHES / GHEC / `ghe.com`
 
@@ -213,6 +217,7 @@ Establish these facts before matching a failure mode:
 | `one-shot-token.so ... __fprintf_chk: symbol not found` | A5 |
 | `unknown shorthand flag: 'd' in -d` from `docker compose up -d` on ARC/DinD | A14 |
 | `Rootless artifact permission repair failed for .../sandbox/firewall/logs` on ARC/DinD | A15 |
+| `[WARN] Rootless artifact permission repair failed` with each attempt taking ~30 s (timeout, not an instant error), followed by cascading `EACCES: permission denied` on chroot-home removal | B10 |
 | `FATAL: http_port: IPv6 is not available` or `Bungled ... [::]:3128` | B3 |
 | `node: command not found` on self-hosted or DinD | A8 or B4 |
 | `none of the git remotes correspond to the GH_HOST environment variable` | C4 |

.github/workflows/self-hosted-runner-doctor.md

@@ -108,6 +108,7 @@ Prefer the narrowest match. Examples:
 - `EACCES: permission denied, mkdir '/tmp/gh-aw/...'` before containers start on a persistent runner → B8 (stale root-owned pre-flight dirs)
 - `FATAL: http_port: IPv6 is not available` → B3
 - `No CA certificates were loaded from the system` in chroot on RHEL/Fedora/Amazon Linux → B9 (missing /etc/pki/ mount)
+- `[WARN] Rootless artifact permission repair failed` with each attempt taking ~30 s (registry timeout, not instant) → B10 (compound tag@digest ref causes Docker to attempt GHCR manifest verification even under `--pull never`)
 - `none of the git remotes correspond to the GH_HOST environment variable` → C4
 - `400 bad request: Authorization header is badly formatted` → C3
 - `400 bad request: Authorization header is badly formatted` on `*.ghe.com` with `COPILOT_API_TARGET=api.business.githubcopilot.com` → C8 (platform-type guard short-circuits token-prefix catalog)
@@ -128,6 +129,8 @@ B8 / github/gh-aw-firewall#5983 — Pre-flight EACCES on persistent runners from
 
 B9 / github/gh-aw-firewall#5783 — RHEL/Amazon Linux CA bundle not accessible in chroot is **fixed** in AWF version including github/gh-aw-firewall#5783. Workaround: copy `/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` to a chroot-visible path and set `SSL_CERT_FILE`/`NODE_EXTRA_CA_CERTS`/`REQUESTS_CA_BUNDLE`/`CURL_CA_BUNDLE`/`GIT_SSL_CAINFO`.
 
+B10 / github/gh-aw-firewall#6025 — `fixArtifactPermissionsForRootless()` compound `tag@digest` ref timeout is **fixed** in AWF version including github/gh-aw-firewall#6025. `resolvePermFixerImageRef()` now returns tag-only refs, eliminating registry I/O during `--pull never` repair.
+
 C7 / #5615 — DIFC proxy enterprise-host awareness for `*.ghe.com` data-residency is not yet implemented in the companion projects; AWF ≥ v0.27.12 provides improved diagnostics (HTTP status + targeted hint) but the underlying cause remains unresolved.
 
 C8 / github/gh-aw-firewall#5872 — Copilot Business `token` prefix short-circuit on GHEC is **fixed** in AWF version including github/gh-aw-firewall#5872.

.github/workflows/shared/self-hosted-failure-modes.md

@@ -48,6 +48,7 @@ Establish these facts before matching a failure mode:
 | B7 | AWF < v0.27.13: unhandled `EACCES` stack trace shows `unlink ... /tmp/awf-<ts>-chroot-home/<path>` (e.g. `.aws/config`, cloud credentials). AWF ≥ v0.27.13: `removeWorkDirectories()` catches the error and emits `[WARN] Failed to remove chroot home directory after permission repair` instead of crashing | In rootless Docker mode the agent container runs with UID namespace remapping. Files created by the agent inside the `chroot-home` temp directory are owned by remapped UIDs. AWF's `removeWorkDirectories()` runs as the unprivileged host runner and `fs.rmSync` fails on these files. | **Partially fixed in AWF v0.27.13** (repair container with CHOWN/DAC_OVERRIDE/FOWNER capabilities); **further fix merged post-v0.27.15** (#5717): in rootless Docker the repair container's `chown` operates within the user namespace and may not change host-level ownership. The post-v0.27.15 fix adds `chmod -R a+rwX` so the host can delete the directory regardless of ownership. Non-fatal if unfixed — leaves an orphan `/tmp/awf-*-chroot-home` dir. **additional hardening** (github/gh-aw-firewall#5766): changes `chown && chmod` to `chown 2>/dev/null; chmod` so `chmod` always runs as a fallback even when `chown` fails within the rootless UID namespace. | `ls -la /tmp/awf-*-chroot-home/` after a rootless run — files owned by non-runner UIDs confirm the mode; upgrade to AWF ≥ v0.27.13; check AWF logs for `[WARN] Failed to remove chroot home directory after permission repair` | #5653, github/gh-aw-firewall#5708, github/gh-aw-firewall#5717, github/gh-aw-firewall#5766 |
 | B8 | `EACCES: permission denied, mkdir '/tmp/gh-aw/sandbox/firewall/logs'` (or any `/tmp/gh-aw/...` path) — failure occurs **before any container starts**, at `writeConfigs` time, on a **persistent self-hosted runner** | A previous AWF run or the Docker daemon left `/tmp/gh-aw/sandbox/firewall/` (or a parent) owned by **root**. With `--network-isolation` now the default, AWF runs without `sudo`, so `mkdirSync` on the root-owned parent fails with EACCES. | **Fixed in AWF (PR github/gh-aw-firewall#5983)**: added `preflight-reclaim.ts` — on non-root invocation, walks upward from the target path to find the first non-writable ancestor and removes it via `sudo rm -rf` with `fs.rmSync` fallback; protected paths (`/`, `/tmp`, `/home/runner`) are never touched. Workaround (older AWF): `sudo rm -rf /tmp/gh-aw/sandbox` before re-running. | `ls -la /tmp/gh-aw/sandbox/firewall/` — dirs owned by root (uid 0) confirm the mode; `docker info | grep -i rootless` | github/gh-aw-firewall#5983 |
 | B9 | `No CA certificates were loaded from the system` — Copilot CLI or other HTTPS tools fail inside AWF chroot on RHEL, Fedora, or Amazon Linux runners; all HTTPS traffic returns TLS verification errors | AWF chroot mounts only Debian/Ubuntu CA paths (`/etc/ssl:ro`, `/etc/ca-certificates:ro`). On RHEL/Amazon Linux the system CA bundle lives under `/etc/pki/ca-trust/` which is not mounted. | **Fixed in AWF (PR github/gh-aw-firewall#5783)**: `copy_system_ca_bundle()` in agent entrypoint detects the CA bundle from 5 candidate paths (Debian, RHEL, Fedora, macOS, Alpine), copies it to `/tmp/awf-lib/system-ca-certificates.crt` if not directly accessible, and sets `SSL_CERT_FILE`, `NODE_EXTRA_CA_CERTS`, `REQUESTS_CA_BUNDLE`, `CURL_CA_BUNDLE`, `GIT_SSL_CAINFO`. Workaround: copy `/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` to a chroot-visible path and set those env vars. | `ls /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem` — present on RHEL/Amazon Linux confirms the mode | github/gh-aw-firewall#5733, github/gh-aw-firewall#5783 |
+| B10 | `[WARN] Rootless artifact permission repair failed for .../sandbox/firewall/logs (exit 1)` × 3 directories, each taking exactly ~30 s; total ~90 s wasted; cascading `EACCES: permission denied` / `Failed to remove chroot home directory after permission repair` | `fixArtifactPermissionsForRootless()` builds compound `tag@digest` image refs (e.g. `agent:0.27.22@sha256:55f065...`) for its `docker run --pull never` repair container. Despite `--pull never`, Docker still attempts registry manifest verification for compound refs; when GHCR credentials are unavailable (cleaned in an earlier workflow step or expired) the verification TCP-connects and times out (~30 s per directory). | **Fixed in AWF (PR github/gh-aw-firewall#6025)**: `resolvePermFixerImageRef()` now strips the `@sha256:...` digest and uses a tag-only ref. `--pull never` with a tag-only ref skips all registry I/O. Upgrade to AWF version that includes github/gh-aw-firewall#6025. Workaround (older AWF): ensure GHCR credentials are available until after the AWF cleanup step. | `[WARN] Rootless artifact permission repair failed` messages each followed by exactly ~30 s delay in the workflow log; `docker pull --dry-run agent:...@sha256:...` times out while `docker inspect agent:...` succeeds | github/gh-aw-firewall#6025 |
 
 ## Category C — GHES / GHEC / `ghe.com`
 
@@ -81,6 +82,7 @@ Establish these facts before matching a failure mode:
 | `one-shot-token.so ... __fprintf_chk: symbol not found` | A5 |
 | `unknown shorthand flag: 'd' in -d` from `docker compose up -d` on ARC/DinD | A14 |
 | `Rootless artifact permission repair failed for .../sandbox/firewall/logs` on ARC/DinD | A15 |
+| `[WARN] Rootless artifact permission repair failed` with each attempt taking ~30 s (timeout, not an instant error), followed by cascading `EACCES: permission denied` on chroot-home removal | B10 |
 | `FATAL: http_port: IPv6 is not available` or `Bungled ... [::]:3128` | B3 |
 | `node: command not found` on self-hosted or DinD | A8 or B4 |
 | `none of the git remotes correspond to the GH_HOST environment variable` | C4 |