opencode: server error after sending prompt

[marcv81]

Nixpkgs version

nixpkgs-unstable @ 02f5696

Describe the bug

When running opencode and sending a prompt, I immediately get a server error message (pop up in the top right corner of the screen). My prompt is not processed. The exact message is as follows.

Failed to send prompt
Unexpected server error. Check server logs for details.

Restarting the server didn't fix the issue. Neither did removing the opencode cache. Removing plugins and providers/models from my opencode config didn't help either. The problems happens with every model I tried (Big Pickle and a self-hosted model).

I didn't find anything useful in the logs. I am not exactly sure what to look for, and I would be happy to provide additional info if someone can point me in the right direction.

I thought 2b7f86f was the problem, but it is not. My apologies @GaetanLepage 🙏

I bisected and the commit 0feb034 introduces the issue: opencode works well with the previous commit, but not from that commit onward. It makes sense as opencode depends on bun. cc @adamcstephens

Steps to reproduce

My home-manager config: https://github.com/marcv81/home-manager @ 1665f259483f7c0f857478dce5c2c52274104bf8.

Expected behaviour

opencode processes prompts without any error.

Screenshots

No response

Relevant log output

Additional context

No response

System metadata

• system: "x86_64-linux"
• host os: Linux 7.0.0-31-generic, Ubuntu, 26.04 (Resolute Raccoon), nobuild
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.35.2
• channels(root): "nixpkgs"
• nixpkgs: /nix/store/1w9ks0pax95r7lvd9djf9gqxrw7jzgqp-nixpkgs/nixpkgs

Notify maintainers

opencode: @delafthi @DuskyElf @graham33 @superherointj
bun: @DAlperin @06kellyjac @thilobillerbeck @cdmistman @diogomdp

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• I assert that this is a bug and not a support request.
• I assert that this is not a duplicate of an existing issue.
• I assert that I have read the NixOS Code of Conduct and agree to abide by it.
• I assert that I have read the automation/AI policy and that this issue report complies with it.

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[delafthi]

Maybe related to the transition from the stable channel to the production channel, see #558549. Can you confirm that? Probably not related to that. I get the same error when preventing the DB transition with NIXPKGS_OPENCODE_DISABLE_LEGACY_DB_WORKAROUND=1.

[delafthi]

Can confirm. This seems to be the issue:

timestamp=2026-09-14T15:27:52.129Z level=ERROR run=991a1b68 message=failed ref=err_f3ae54dc error="TypeError: undefined is not an object (evaluating 'a.name')" cause="TypeError: undefined is not an object (evaluating 'a.name')\n    at resolve (/$bunfs/root/chunk-5z974vrf.js:2:1659)\n    at a (/$bunfs/root/chunk-5z974vrf.js:2:936)\n    at map (native:1:11)\n    at <anonymous> (/$bunfs/root/chunk-5z974vrf.js:2:1626)\n    at a (/$bunfs/root/chunk-5z974vrf.js:2:1166)\n    at map (native:1:11)\n    at <anonymous> (/$bunfs/root/chunk-5z974vrf.js:2:1626)\n    at a (/$bunfs/root/chunk-5z974vrf.js:2:1166)\n    at map (native:1:11)\n    at <anonymous> (/$bunfs/root/chunk-5z974vrf.js:2:1390)\n    at SystemPrompt.environment (/$bunfs/root/chunk-p5jbh4gq.js:50:13096)\n    at SystemPrompt.environment (definition) (/$bunfs/root/chunk-p5jbh4gq.js:4:14254)\n    at SessionPrompt.run (/$bunfs/root/chunk-p5jbh4gq.js:50:14576)\n    at SessionPrompt.run (definition) (/$bunfs/root/chunk-p5jbh4gq.js:50:10099)\n    at SessionRunState.ensureRunning (/$bunfs/root/chunk-p5jbh4gq.js:50:14545)\n    at SessionRunState.ensureRunning (definition) (/$bunfs/root/chunk-p5jbh4gq.js:2:6720)\n    at SessionPrompt.loop (/$bunfs/root/chunk-p5jbh4gq.js:50:9849)\n    at SessionPrompt.loop (definition) (/$bunfs/root/chunk-p5jbh4gq.js:50:14481)\n    at SessionPrompt.prompt (/$bunfs/root/chunk-pgb5pfcx.js:6:11695)\n    at SessionPrompt.prompt (definition) (/$bunfs/root/chunk-p5jbh4gq.js:50:9462)"

[adamcstephens]

Probably better to ping the author of the bun upgrade, as they have more context than I. cc @hesprs

[hesprs]

Probably related:

• SystemPrompt.environment anomalyco/opencode#48372
• Undefined layer node dependency fails with an unattributable TypeError anomalyco/opencode#48819
• fix(core): break filesystem cycle in compiled prompts anomalyco/opencode#48397

[adamcstephens]

GPT-5.6-Sol led me to test disabling minification and/or splitting. Disabling the latter seems to fix it.

diff --git i/pkgs/by-name/op/opencode/package.nix w/pkgs/by-name/op/opencode/package.nix
index 316bd5233cbb..6f94dd5095b5 100644
--- i/pkgs/by-name/op/opencode/package.nix
+++ w/pkgs/by-name/op/opencode/package.nix
@@ -110,6 +110,10 @@ stdenv.mkDerivation (finalAttrs: {
         --replace-fail \
         'if (item.os === process.platform && item.arch === process.arch && !item.abi)' \
         'if (false)'
+
+      # fix for bun 1.4.x
+      substituteInPlace packages/opencode/script/build.ts \
+        --replace-fail 'splitting: true,' 'splitting: false,'
     '';

   nativeBuildInputs = [

I did first try regenerating the node_modules hash. It doesn't seem to be necessary, but I thought it a sign that it did change.

[hesprs]

According to the upstream issues, I suppose this is an OpenCode-side bug that affects all users compiling OpenCode with Bun 1.4.2, not only Nix users.

[adamcstephens]

Yeah, seems like it. I also just tested anomalyco/opencode#48397 as a patch, and that also resolves the issue.

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/opencode-server-error-workaround/80088/1

[adamcstephens]

I've shared two workable solutions above, but I think the opencode maintainers should decide their path forward.

[ser]

package upgrade to the newest version should close this issue, 1.18.31

[cmm]

package upgrade to the newest version should close this issue, 1.18.31

it does not