Plugin loader incorrectly appends @latest to GitHub references

[frankekn]

Description

When using a GitHub-hosted plugin like github:owner/repo, OpenCode appends @latest to form github:owner/repo@latest, which Bun cannot resolve.

Root Cause

In packages/opencode/src/plugin/index.ts:

const lastAtIndex = plugin.lastIndexOf("@")
const pkg = lastAtIndex > 0 ? plugin.substring(0, lastAtIndex) : plugin
const version = lastAtIndex > 0 ? plugin.substring(lastAtIndex + 1) : "latest"
plugin = await BunProc.install(pkg, version)  // becomes pkg + "@" + version

This creates github:owner/repo@latest which Bun fails to resolve with:

error: GET https://api.github.com/repos//latest/tarball/ - 404
error: github:owner/repo@latest failed to resolve

Bun's GitHub Dependency Format

According to Bun documentation, GitHub dependencies use # for version/tag specifiers, not @:

{
  "lodash": "git+ssh://github.com/lodash/lodash.git#4.17.21",
  "zod": "github:colinhacks/zod"
}

The @ syntax is only for npm registry packages.

Reproduction

bun add "github:lodash/lodash@latest"
# error: GET https://api.github.com/repos//latest/tarball/ - 404

bun add "github:lodash/lodash"
# Success - installs from default branch

bun add "github:lodash/lodash#main"
# Success - installs from main branch

Suggested Fix

Check if the plugin string starts with github: or git+ before appending version:

const isGitDependency = plugin.startsWith("github:") || plugin.startsWith("git+") || plugin.startsWith("git://")

if (isGitDependency) {
  // Don't append @latest for git dependencies
  // Or use # instead: pkg + "#" + version
  plugin = await BunProc.install(pkg, undefined)
} else {
  plugin = await BunProc.install(pkg, version)
}

Workaround

Publish the plugin to npm registry instead of using GitHub reference.