fix(skill): dedupe symlinked external skill paths

packages/opencode/src/skill/skill.ts

@@ -55,14 +55,19 @@ export namespace Skill {
   export const state = Instance.state(async () => {
     const skills: Record<string, Info> = {}
     const dirs = new Set<string>()
+    const seen = new Set<string>()
 
     const addSkill = async (match: string) => {
-      const md = await ConfigMarkdown.parse(match).catch((err) => {
+      const file = Filesystem.resolve(match)
+      if (seen.has(file)) return
+      seen.add(file)
+
+      const md = await ConfigMarkdown.parse(file).catch((err) => {
         const message = ConfigMarkdown.FrontmatterError.isInstance(err)
           ? err.data.message
-          : `Failed to parse skill ${match}`
+          : `Failed to parse skill ${file}`
         Bus.publish(Session.Event.Error, { error: new NamedError.Unknown({ message }).toObject() })
-        log.error("failed to load skill", { skill: match, err })
+        log.error("failed to load skill", { skill: file, err })
         return undefined
       })
 
@@ -76,16 +81,16 @@ export namespace Skill {
         log.warn("duplicate skill name", {
           name: parsed.data.name,
           existing: skills[parsed.data.name].location,
-          duplicate: match,
+          duplicate: file,
         })
       }
 
-      dirs.add(path.dirname(match))
+      dirs.add(path.dirname(file))
 
       skills[parsed.data.name] = {
         name: parsed.data.name,
         description: parsed.data.description,
-        location: match,
+        location: file,
         content: md.content,
       }
     }

packages/opencode/test/skill/skill.test.ts

@@ -386,3 +386,39 @@ description: A skill in the .opencode/skills directory.
     },
   })
 })
+
+test("deduplicates symlinked skill directories by canonical path", async () => {
+  await using tmp = await tmpdir({
+    git: true,
+    init: async (dir) => {
+      const agentDir = path.join(dir, ".agents", "skills", "shared-skill")
+      const claudeDir = path.join(dir, ".claude", "skills", "shared-skill")
+      await fs.mkdir(agentDir, { recursive: true })
+      await fs.mkdir(path.dirname(claudeDir), { recursive: true })
+      await Bun.write(
+        path.join(agentDir, "SKILL.md"),
+        `---
+name: shared-skill
+description: A shared skill.
+---
+
+# Shared Skill
+`,
+      )
+      await fs.symlink(agentDir, claudeDir, process.platform === "win32" ? "junction" : "dir")
+      return { agentDir }
+    },
+  })
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const skills = await Skill.all()
+      const dirs = await Skill.dirs()
+      expect(skills.length).toBe(1)
+      expect(skills[0].location).toBe(path.join(tmp.extra.agentDir, "SKILL.md"))
+      expect(dirs).toContain(tmp.extra.agentDir)
+      expect(dirs.length).toBe(1)
+    },
+  })
+})