Regression in 1.18.30: every prompt crashes with TypeError in SystemPrompt.environment ("a.name") — 1.18.18 works fine #48645

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1. github-actions

   assigned

   nexxeln

   on Sep 12, 2026
2. github-actions commented on Sep 12, 2026

   

   github-actionsBot

   on Sep 12, 2026 – with GitHub Actions

   Contributor

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   This issue might be a duplicate of existing issues. Please check:

   • SystemPrompt.environment #48372: Same crash — TypeError: undefined is not an object (evaluating 'a.name') in SystemPrompt.environment on v1.18.30, reproduces on every prompt with a clean config/home, identical stack trace.
3. fabriziomartini commented on Sep 13, 2026

   

   fabriziomartini

   on Sep 13, 2026

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   Confirming this on macOS via Homebrew too. Same crash:
   TypeError: undefined is not an object (evaluating 'a.name')

   Reproducible even with empty config and built-in provider —
   verified it's not related to any custom provider setup.

   Downgrading to 1.18.15 via npm (npm install -g [email protected])
   fixes it completely.

   👍React with 👍2Reacted by abavoil and Ruben Laguna
4. hollodotme commented on Sep 13, 2026

   

   hollodotme

   on Sep 13, 2026

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   I analysed the issue with Claude, here's the summary and workaround.

   opencode v1.18.30: SystemPrompt.environment crashes with TypeError: undefined is not an object (evaluating 'a.name')

   Description

   opencode v1.18.30 crashes when building the system prompt environment. The error occurs in the embedded v2 model catalog resolution code during nested .map() iterations, where an array element is undefined but the code expects an object with a .name property.

   This makes opencode completely unusable — any prompt submission fails with:
   ▎ Failed to send prompt
   ▎ Unexpected server error. Check server logs for details.

   The error is not caused by user configuration, plugins, cache, or project state. It reproduces from any directory, even with --pure (no external plugins).

   Stack trace (from ~/.local/share/opencode/log/opencode.log)

     TypeError: undefined is not an object (evaluating 'a.name')
         at resolve (/$bunfs/root/chunk-36bwgd4p.js:2:1659)
         at a (/$bunfs/root/chunk-36bwgd4p.js:2:936)
         at map (native:1:11)
         ...
         at SystemPrompt.environment (/$bunfs/root/chunk-y88jw4qv.js:50:13096)

   Reproduction

   # Confirm version
   opencode --version
   # Expected: 1.18.30
   
   # Reproduce the crash (no project or config needed)
   cd /tmp && mkdir -p opencode-bug && cd opencode-bug && git init -q
   opencode debug v2 --pure
   # Output: Error: Unexpected error — undefined is not an object (evaluating 'a.name')
   

   Proof that v1.18.29 is not affected

   # Install v1.18.29 via curl
   opencode upgrade 1.18.29 -m curl
   
   # Run directly (bypass any brew-installed 1.18.30)
   ~/.opencode/bin/opencode --version
   # Output: 1.18.29
   
   ~/.opencode/bin/opencode debug v2 --pure
   # Output: { "providers": [ ... ] }   ← works fine
   

   Workaround

   If opencode was installed via brew, unlink the broken v1.18.30 and fall back to v1.18.29 installed via curl:

   opencode upgrade 1.18.29 -m curl
   brew unlink opencode
   opencode --version  # should now show 1.18.29
   

   Environment

   • opencode v1.18.30 (Homebrew, macOS arm64)
   • macOS Darwin 25.6.0
   • Regression introduced between v1.18.29 and v1.18.30

   👍React with 👍4Reacted by Alper Kanat, Dante Alferez Condori, Lukas Gierth and Jeremy Grecu
5. vilherda commented on Sep 13, 2026

   

   vilherda

   on Sep 13, 2026

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   Also affected on macOS. I ran an A/B plus a build-to-build comparison that narrows this down further, so posting the data here since this is the "regression" issue.

   1. The regression window is exactly one release: 1.18.29 → 1.18.30

   Same machine, same ~/.config/opencode, same directory, back to back:

   Version	Result
   1.18.29 ([email protected], unpacked to a temp dir, not installed)	✅ prompt completes normally
   1.18.30 (Homebrew bottle 1.18.30_1)	❌ TypeError: undefined is not an object (evaluating 'a.name')

   So it is not "somewhere between 1.18.18 and 1.18.30" — 1.18.29 is good and 1.18.30 is bad.

   2. It is unconditional on the CLI build

   Every one of these crashes identically, all with --pure:

   Config	Directory	Result
   my real config	non-git dir	crash
   my real config	git repo	crash
   stock {"$schema":"https://opencode.ai/config.json"} + fresh XDG_CONFIG_HOME/XDG_DATA_HOME	non-git dir	crash
   stock + fresh XDG	git repo	crash

   Ruled out: plugins (--pure), MCP servers, LSPs, git vs non-git, and the references block from #48809 (mine is commented out). opencode agent list --pure does not crash for me — only the prompt path does, i.e. SystemPrompt.environment.

   3. The bun-compiled binary is affected; the Electron build of the same 1.18.30 is not

   This looks like the most useful datapoint. I have both installed:

   • /opt/homebrew/bin/opencode → 1.18.30, bun single-file binary → crashes on every prompt
   • /Applications/OpenCode.app → 1.18.30 (Electron/Node bundle) → never crashed once

   Over the exact window in which 81 level=ERROR a.name crashes were logged from five separate CLI/TUI processes, the desktop app's server in the same shared log kept logging booting location services successfully for many directories, and produced zero crashes.

   The Electron app.asar contains booting location services and SystemPrompt.environment but zero occurrences of $bunfs or chunk-36bwgd4p — same source, different bundle. Every stack trace in this issue and in #48803 / #48811 / #48809 / #48372 is /$bunfs/root/chunk-*.js.

   That points at a bundling / module-initialisation artifact of the bun compile step rather than a source-level logic bug — consistent with the failure mode below. (Stated as a hypothesis; I have not bisected the source.)

   4. Where it dies

   From the bundled code, the location-service layer group is a module-level constant:

   // chunk-rbqz2b3d.js
   var e8 = Gh([rc, jB, OA, h2, t7, eB, T2, qE, /* ... */ , C_]);
   
   function Jv(e = []) {
     return J(os, l6((t) => {
       let n = e.concat([[rc, Tq(t)]]),
           i = Uq(e8, Wp.values.global, n);          // <-- hoist tagged layers
       return U2(i.node).pipe(ak, MF(() => Se("booting location services", {...})), dt(U2(i.hoisted)))
     }, { idleTimeToLive: "60 minutes" }))
   }

   Uq walks node.dependencies and hits, in chunk-36bwgd4p.js:

   resolve: (a) => s.get(a.name) ?? a     // a === undefined

   So one entry of a deps: [...] array inside e8's graph is undefined at module-eval time. A stale/undefined binding from a circular chunk import would produce exactly this, and would also explain why only the bun bundle is affected while the Node bundle of the same commit is fine.

   Net effect: the location runtime never boots, so SystemPrompt.environment throws and no prompt ever reaches a model.

   Environment

   • macOS 26.6.2 (build 25G83), Darwin 25.6.0, arm64
   • opencode 1.18.30, Homebrew bottle 1.18.30_1
   • Crashing chunk in this build: chunk-36bwgd4p.js
   • Workaround in use: run 1.18.29

   Reproduction

   BASE=$(mktemp -d); mkdir -p "$BASE/cfg/opencode" "$BASE/data/opencode" "$BASE/dir"
   cp ~/.local/share/opencode/auth.json "$BASE/data/opencode/"
   printf '{"$schema":"https://opencode.ai/config.json"}' > "$BASE/cfg/opencode/opencode.json"
   cd "$BASE/dir" && XDG_CONFIG_HOME="$BASE/cfg" XDG_DATA_HOME="$BASE/data" \
     opencode run --pure --print-logs "say PONG"

   1.18.30 → a.name in SystemPrompt.environment. 1.18.29 → PONG.

   👍React with 👍1Reacted by Anthony J
6. DanCanCos commented on Sep 14, 2026

   

   DanCanCos

   on Sep 14, 2026

   Last edited by DanCanCos

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   MacOS, same issue. After lots of troubleshooting, uninstalling the Homebrew maintained formula with brew uninstall opencode and Installing from the recommended tap with brew install anomalyco/tap/opencode resolved this issue for me. Running 1.18.30 just fine now. Uninstalling did not touch my config or session data.

   👍React with 👍22Reacted by Jan Rabe, WZHMAT1, Eugene Hong, Yazdan Mohammadi, Gerard Montes, Michael Chang, Rajesh Hegde, Nitya Sunkad, Bastien, Greg and 12 more

   🚀React with 🚀7Reacted by Jan Rabe, Michael Chang, abavoil, Raphael Caldas, moreindirection, alx-ul and Anthony J
7. jgrecu commented on Sep 15, 2026

   

   jgrecu

   on Sep 15, 2026

   Last edited by jgrecu

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   MacOS, same issue. After lots of troubleshooting, uninstalling the Homebrew maintained formula with brew uninstall opencode and Installing from the recommended tap with brew install anomalyco/tap/opencode resolved this issue for me. Running 1.18.30 just fine now. Uninstalling did not touch my config or session data.

   that is because a new version is installed:

   ❯ brew uninstall opencode
   Uninstalling /opt/homebrew/Cellar/opencode/1.18.30_1... (7 files, 143.2MB)
   ❯ brew install anomalyco/tap/opencode
   ==> Tapping anomalyco/tap
   Cloning into '/opt/homebrew/Library/Taps/anomalyco/homebrew-tap'...
   Tapped 1 cask and 3 formulae (16 files, 1.4MB).
   ==> Trusted formula anomalyco/tap/opencode
   ==> Would install 1 formula:
   opencode
   ==> Fetching downloads for: opencode
   ✔︎ Formula opencode (1.18.31) Verified 46.3MB/ 46.3MB
   ==> Installing opencode from anomalyco/tap
   🍺 /opt/homebrew/Cellar/opencode/1.18.31: 4 files, 144.5MB, built in 3 seconds

   I can confirm this version does not have the bug/issue

   👍React with 👍2Reacted by Sean Halpin and Konrad Stępień
8. DanCanCos commented on Sep 15, 2026

   

   DanCanCos

   on Sep 15, 2026

   Last edited by DanCanCos

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   that is because a new version is installed

   1.18.31 was released after this comment was made, but I'm glad the new version is working for you.

   $ brew info opencode
   ==> opencode ✔: stable 1.18.30

   👍React with 👍1Reacted by Jeremy Grecu
9. Xyz00777 commented on Sep 15, 2026

   

   Xyz00777

   on Sep 15, 2026

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   can confirm still broken in 1.18.31 (at least on nixos).

   👍React with 👍8Reacted by Connor Grady, MiguVT, Chris Hill, Matthew Turney, Valdemar José Ceccon Junior, dominictdavies, ar175-lol and Daniel
10. fabriziomartini commented on Sep 15, 2026

    

    fabriziomartini

    on Sep 15, 2026

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    Confirming 1.18.31 fixes this on macOS via npm as well (not just via the Homebrew tap mentioned above).

    Tested in isolation first with the curl-based upgrade (~/.opencode/bin/opencode), before touching the global install:

    • opencode run --pure "say PONG" → PONG (no crash)
    • Real config with a custom OpenAI-compatible provider, tool calling (date command), and longer prompts → all working correctly

    Then made it permanent:
    npm install -g --allow-scripts=opencode-ai [email protected]
    opencode --version → 1.18.31
    opencode run "ciao" → works fine

    macOS, npm-managed install (not Homebrew).
11. creativecomposer commented on Sep 17, 2026

    

    creativecomposer

    on Sep 17, 2026

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    MacOS, same issue. After lots of troubleshooting, uninstalling the Homebrew maintained formula with brew uninstall opencode and Installing from the recommended tap with brew install anomalyco/tap/opencode resolved this issue for me. Running 1.18.30 just fine now. Uninstalling did not touch my config or session data.

    In MacOS, I can confirm that this solution works. Great work @DanCanCos 🥇
12. rekram1-node

    closed this as completedin #50439on Sep 21, 2026
13. j5ik2o

    added a commit that references this issue on Sep 22, 2026

    chore(nix): bump nixpkgs to pick up opencode 1.18.31

    ...

    b885842
14. MaxMac99

    added a commit that references this issue on Sep 22, 2026

    fix(opencode): build 1.18.31 without bun code splitting

    ...

    9c258cd
15. adriangs1996

    added a commit that references this issue on Oct 2, 2026

    Follow OpenCode as a built-in agent

    ...

    f313a6f