fix: surface Docker image retry instructions in MCP compile error message by Copilot · Pull Request #19792 · github/gh-aw

Copilot · 2026-03-06T02:56:56Z

The compile MCP tool swallowed useful retry instructions when Docker images weren't cached — the detailed message from CheckAndPrepareDockerImages was placed in jsonrpc.Error.Data, which the Copilot CLI MCP client never renders. Users only saw "docker images not ready" with no guidance.

Change

Move the full error message into the Message field of the JSON-RPC error:

// Before — retry instructions hidden in Data field
return nil, nil, newMCPError(jsonrpc.CodeInternalError, "docker images not ready", err.Error())

// After — retry instructions visible in Message field
return nil, nil, newMCPError(jsonrpc.CodeInternalError, err.Error(), nil)

The error message from CheckAndPrepareDockerImages already contains the full user-actionable text:

Docker images are being downloaded. Please wait and retry the compile command.

Started downloading: actionlint
Retry in 15-30 seconds.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

https://api.github.com/graphql
- Triggering command: /usr/bin/gh /usr/bin/gh api graphql -f query=query($owner: String!, $name: String!) { repository(owner: $owner, name: $name) { hasDiscussionsEnabled } } -f owner=github -f name=gh-aw GO111MODULE x_amd64/vet git rev-�� --show-toplevel OhGqih4/C5EvyQA3x6PSYtu1bbVC /usr/bin/git o actions/setup-git GO111MODULE 64/pkg/tool/linu--show-toplevel git (http block)
https://api.github.com/repos/actions/ai-inference/git/ref/tags/v1
- Triggering command: /usr/bin/gh gh api /repos/actions/ai-inference/git/ref/tags/v1 --jq .object.sha k/gh-aw/gh-aw/.github/workflows/blog-auditor.md -buildtags (http block)
https://api.github.com/repos/actions/checkout/git/ref/tags/v3
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v3 --jq .object.sha runs/20260306-030205-26755/test-1144262647/.github/workflows /tmp/go-build2506171960/b086/vet.cfg ache/node/24.14.0/x64/bin/node l GO111MODULE 64/bin/go /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/vet t-30�� sistency_GoAndJavaScript570293675/001/test-complex-frontmatter-w-test.timeout=10m0s /tmp/go-build2506171960/b254/vet.cfg /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/vet 7446173/b377/_pkgit GO111MODULE 64/bin/go /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/actions/checkout/git/ref/tags/v5
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v5 --jq .object.sha g_.a GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet env ShyZf04-J .cfg x_amd64/compile GOINSECURE GOMOD GOMODCACHE x_amd64/compile (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v5 --jq .object.sha --show-toplevel x_amd64/compile /usr/bin/git -json GO111MODULE x_amd64/vet git rev-�� --show-toplevel 1bnA3ry/amyila423AJljWL-wbSP /usr/bin/git -json GO111MODULE x_amd64/vet /usr/bin/git (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v5 --jq .object.sha --show-toplevel 64/pkg/tool/linux_amd64/vet /usr/bin/git -json .cfg 64/pkg/tool/linu--show-toplevel git rev-�� --show-toplevel 64/pkg/tool/linux_amd64/vet /usr/bin/git -json GO111MODULE ache/go/1.25.0/x--show-toplevel git (http block)
https://api.github.com/repos/actions/checkout/git/ref/tags/v6
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v6 --jq .object.sha /tmp/gh-aw-test-runs/20260306-030205-26755/test-2826858097/.github/workflows rev-parse ache/node/24.14.0/x64/bin/node prettier --check 64/bin/go infocmp t-54�� k/gh-aw/gh-aw/.github/workflows/audit-workflows.md git ache/node/24.14.0/x64/bin/node --porcelain sh 64/bin/go ache/node/24.14.0/x64/bin/node (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v6 --jq .object.sha /tmp/gh-aw-test-runs/20260306-030205-26755/test-1567730566/.github/workflows config /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/compile remote.origin.urgit GOPROXY 64/bin/go /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/compile -o /tmp/go-build2506171960/b422/_pkg_.a -trimpath /opt/hostedtoolcache/node/24.14.0/x64/bin/node -p main -lang=go1.25 node (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/checkout/git/ref/tags/v6 --jq .object.sha --show-toplevel 64/pkg/tool/linux_amd64/vet /usr/bin/git -json .cfg 64/pkg/tool/linu--show-toplevel git rev-�� --show-toplevel 64/pkg/tool/linux_amd64/vet /usr/bin/git -json .cfg 64/pkg/tool/linu--show-toplevel git (http block)
https://api.github.com/repos/actions/github-script/git/ref/tags/v8
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v8 --jq .object.sha -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE node /opt�� prettier --check 64/bin/go --ignore-path .prettierignore 64/bin/go go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v8 --jq .object.sha che/go-build/bf/bf0813d7488cf446GOINSECURE GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc/tmp/go-build2506171960/b206/vet.cfg -o /tmp/go-build2487446173/b391/_pkGOINSECURE -trimpath 64/bin/go -p main -lang=go1.25 go (http block)
- Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v8 --jq .object.sha k/gh-aw/gh-aw/pkg/timeutil/formaGOINSECURE k/gh-aw/gh-aw/pkg/timeutil/formaGOMOD 64/bin/go GOSUMDB GOWORK 64/bin/go /opt/hostedtoolc/tmp/go-build2506171960/b265/vet.cfg -o /tmp/go-build2487446173/b412/_pkGOINSECURE -trimpath 64/bin/go -p github.com/githu-test.testlogfile=/tmp/go-build2506171960/b001/testlog.txt -lang=go1.25 go (http block)
https://api.github.com/repos/actions/setup-go/git/ref/tags/v4
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/v4 --jq .object.sha /tmp/gh-aw-test-runs/20260306-030205-26755/test-853843346/.github/workflows rev-parse /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/compile "prettier" --chegit GOPROXY 64/bin/go /opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/compile -o /tmp/go-build2506171960/b418/_pkg_.a -trimpath ache/node/24.14.0/x64/bin/node -p github.com/githurev-parse -lang=go1.25 ache/node/24.14.0/x64/bin/node (http block)
https://api.github.com/repos/actions/setup-node/git/ref/tags/v4
- Triggering command: /usr/bin/gh gh api /repos/actions/setup-node/git/ref/tags/v4 --jq .object.sha --show-toplevel -tests /tmp/go-build2506171960/b416/sliceutil.test prettier --check 64/bin/go /tmp/go-build2506171960/b416/sliceutil.test -tes�� -test.paniconexit0 -test.v=true /usr/bin/gh -test.timeout=10git -test.run=^Test -test.short=true--show-toplevel gh (http block)
https://api.github.com/repos/actions/upload-artifact/git/ref/tags/v4
- Triggering command: /usr/bin/gh gh api /repos/actions/upload-artifact/git/ref/tags/v4 --jq .object.sha -json stmain.go ache/go/1.25.0/x64/pkg/tool/linux_amd64/link GOINSECURE GOMOD GOMODCACHE ache/go/1.25.0/x64/pkg/tool/linux_amd64/link -uns�� 0205-26755/test-2917318497 /tmp/go-build2506171960/b174/vet.cfg 6171960/b413/importcfg.link GOSUMDB GOWORK 64/bin/go R_UliyopLjxfi/ZevTDm5WWeLBmz850apU/LCdcE90MYeg_f3TBb3HV/wjRJCy6R_UliyopLjxfi (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/1/artifacts
- Triggering command: /usr/bin/gh gh run download 1 --dir test-logs/run-1 GO111MODULE 64/pkg/tool/linu-nilfunc GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linu-tests env -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/12345/artifacts
- Triggering command: /usr/bin/gh gh run download 12345 --dir test-logs/run-12345 GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet estl�� -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/12346/artifacts
- Triggering command: /usr/bin/gh gh run download 12346 --dir test-logs/run-12346 GO111MODULE 64/pkg/tool/linu-nolocalimports GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linu/tmp/go-build2506171960/b422/_testmain.go estl�� -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/2/artifacts
- Triggering command: /usr/bin/gh gh run download 2 --dir test-logs/run-2 GO111MODULE 64/pkg/tool/linux_amd64/link GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/link env aw.test GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/3/artifacts
- Triggering command: /usr/bin/gh gh run download 3 --dir test-logs/run-3 GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linutest@example.com env -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/4/artifacts
- Triggering command: /usr/bin/gh gh run download 4 --dir test-logs/run-4 GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet env -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/runs/5/artifacts
- Triggering command: /usr/bin/gh gh run download 5 --dir test-logs/run-5 GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet env -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/actions/workflows
- Triggering command: /usr/bin/gh gh workflow list --json name,state,path npx prettier --c-errorsas GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go sh -c "prettier" --che-errorsas node 64/bin/go tierignore --write 64/bin/go go (http block)
- Triggering command: /usr/bin/gh gh run list --json databaseId,number,url,status,conclusion,workflowName,createdAt,startedAt,updatedAt,event,headBranch,headSha,displayTitle --workflow nonexistent-workflow-12345 --limit 100 --write 64/bin/go go env -json GO111MODULE 64/bin/go GOINSECURE GOMOD GOMODCACHE go (http block)
- Triggering command: /usr/bin/gh gh run list --json databaseId,number,url,status,conclusion,workflowName,createdAt,startedAt,updatedAt,event,headBranch,headSha,displayTitle --workflow nonexistent-workflow-12345 --limit 6 GOMOD GOMODCACHE x_amd64/vet [:up�� [:lower:] GOPROXY 64/pkg/tool/linux_amd64/vet GOSUMDB GOWORK 64/bin/go 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/git/ref/tags/v1.0.0
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v1.0.0 --jq .object.sha -json GO111MODULE At,event,headBranch,headSha,displayTitle GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet env -json .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/github/gh-aw/git/ref/tags/v1.2.3
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v1.2.3 --jq .object.sha -json GOCACHE 64/bin/go -d (http block)
https://api.github.com/repos/github/gh-aw/git/ref/tags/v2.0.0
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v2.0.0 --jq .object.sha -mod=readonly -e 64/bin/go -d (http block)
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v2.0.0 --jq .object.sha /tmp/go-build2487446173/b354/_pkGOINSECURE -trimpath 64/bin/go -d github.com/githu-atomic -lang=go1.25 go env -json GO111MODULE x_amd64/link GOINSECURE GOMOD GOMODCACHE x_amd64/link (http block)
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v2.0.0 --jq .object.sha /tmp/go-build2487446173/b378/_pkGOINSECURE -trimpath 64/bin/go -p github.com/stret-atomic -lang=go1.17 go env -json GO111MODULE x_amd64/link GOINSECURE GOMOD GOMODCACHE x_amd64/link (http block)
https://api.github.com/repos/github/gh-aw/git/ref/tags/v3.0.0
- Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v3.0.0 --jq .object.sha erignore sh 64/bin/go "prettier" --wri/opt/hostedtoolcache/go/1.25.0/x64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/nonexistent/action/git/ref/tags/v999.999.999
- Triggering command: /usr/bin/gh gh api /repos/nonexistent/action/git/ref/tags/v999.999.999 --jq .object.sha -json GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet env 2826858097/.github/workflows .cfg 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/nonexistent/repo/actions/runs/12345
- Triggering command: /usr/bin/gh gh run view 12345 --repo nonexistent/repo --json status,conclusion GOINSECURE GOMOD GOMODCACHE x_amd64/compile env -json GO111MODULE 64/pkg/tool/linux_amd64/vet GOINSECURE GOMOD GOMODCACHE 64/pkg/tool/linux_amd64/vet (http block)
https://api.github.com/repos/owner/repo/actions/workflows
- Triggering command: /usr/bin/gh gh workflow list --json name,state,path --repo owner/repo 64/bin/go GOSUMDB GOWORK 64/bin/go node /hom�� --check scripts/**/*.js 64/bin/go .prettierignore (http block)
https://api.github.com/repos/owner/repo/contents/file.md
- Triggering command: /tmp/go-build2506171960/b383/cli.test /tmp/go-build2506171960/b383/cli.test -test.testlogfile=/tmp/go-build2506171960/b383/testlog.txt -test.paniconexit0 -test.v=true -test.parallel=4 -test.timeout=10m0s -test.run=^Test -test.short=true GOINSECURE GOMOD GOMODCACHE 7446173/b383/imp-buildtags /hom�� k/gh-aw/gh-aw/pk-errorsas k/gh-aw/gh-aw/pk-ifaceassert 64/bin/go **/*.json --ignore-path ../../../.pretti-bool /opt/hostedtoolc-buildtags (http block)
https://api.github.com/repos/test-owner/test-repo/actions/secrets
- Triggering command: /usr/bin/gh gh api /repos/test-owner/test-repo/actions/secrets --jq .secrets[].name npx prettier --c-errorsas GOPROXY 64/bin/go GOSUMDB GOWORK 64/bin/go sh -c "prettier" --che-errorsas node 64/bin/go tierignore --write 64/bin/go go (http block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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…s not ready Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot

Pull request overview

Surfaces actionable Docker image download/retry instructions to MCP clients by moving detailed guidance from the JSON-RPC Error.Data field into the Error.Message field when Docker images are not yet prepared for compile.

Changes:

Update compile MCP tool error construction to put CheckAndPrepareDockerImages’s full message into jsonrpc.Error.Message (and set Data to nil).

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…19792) Add a note to the compile tool reference explaining that actionlint, zizmor, and poutine require Docker images on first use and that users should wait 15-30 seconds and retry if images are still downloading. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Initial plan

32abfbf

Copilot AI assigned Copilot and pelikhan Mar 6, 2026

Copilot started work on behalf of pelikhan March 6, 2026 02:57 View session

fix: include retry instructions in MCP error message for docker image…

0b80a72

…s not ready Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix error message for docker images not ready~~ fix: surface Docker image retry instructions in MCP compile error message Mar 6, 2026

Copilot finished work on behalf of pelikhan March 6, 2026 03:04

pelikhan approved these changes Mar 6, 2026

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pelikhan marked this pull request as ready for review March 6, 2026 03:09

Copilot AI review requested due to automatic review settings March 6, 2026 03:09

Copilot started reviewing on behalf of pelikhan March 6, 2026 03:10 View session

Copilot AI reviewed Mar 6, 2026

View reviewed changes

Merge branch 'main' into copilot/fix-docker-images-error

f62d0fe

pelikhan merged commit fac1c33 into main Mar 6, 2026
44 checks passed

pelikhan deleted the copilot/fix-docker-images-error branch March 6, 2026 03:33

github-actions bot mentioned this pull request Mar 6, 2026

[docs] Update documentation for features from 2026-03-06 #19805

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fix: surface Docker image retry instructions in MCP compile error message#19792

fix: surface Docker image retry instructions in MCP compile error message#19792
pelikhan merged 3 commits intomainfrom
copilot/fix-docker-images-error

Copilot AI commented Mar 6, 2026 •

edited

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Copilot AI commented Mar 6, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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I tried to connect to the following addresses, but was blocked by firewall rules:

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Copilot AI commented Mar 6, 2026 •

edited

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