core: ensure export command output can be piped without UI interference

packages/opencode/src/cli/cmd/export.ts

@@ -18,10 +18,13 @@ export const ExportCommand = cmd({
   handler: async (args) => {
     await bootstrap(process.cwd(), async () => {
       let sessionID = args.sessionID
+      process.stderr.write(`Exporting session: ${sessionID ?? "latest"}`)
 
       if (!sessionID) {
         UI.empty()
-        prompts.intro("Export session")
+        prompts.intro("Export session", {
+          output: process.stderr,
+        })
 
         const sessions = []
         for await (const session of Session.list()) {
@@ -29,8 +32,12 @@ export const ExportCommand = cmd({
         }
 
         if (sessions.length === 0) {
-          prompts.log.error("No sessions found")
-          prompts.outro("Done")
+          prompts.log.error("No sessions found", {
+            output: process.stderr,
+          })
+          prompts.outro("Done", {
+            output: process.stderr,
+          })
           return
         }
 
@@ -44,6 +51,7 @@ export const ExportCommand = cmd({
             value: session.id,
             hint: `${new Date(session.time.updated).toLocaleString()} • ${session.id.slice(-8)}`,
           })),
+          output: process.stderr,
         })
 
         if (prompts.isCancel(selectedSession)) {
@@ -52,7 +60,9 @@ export const ExportCommand = cmd({
 
         sessionID = selectedSession as string
 
-        prompts.outro("Exporting session...")
+        prompts.outro("Exporting session...", {
+          output: process.stderr,
+        })
       }
 
       try {

packages/opencode/src/util/log.ts

@@ -4,7 +4,9 @@ import { Global } from "../global"
 import z from "zod"
 
 export namespace Log {
-  export const Level = z.enum(["DEBUG", "INFO", "WARN", "ERROR"]).meta({ ref: "LogLevel", description: "Log level" })
+  export const Level = z
+    .enum(["DEBUG", "INFO", "WARN", "ERROR"])
+    .meta({ ref: "LogLevel", description: "Log level" })
   export type Level = z.infer<typeof Level>
 
   const levelPriority: Record<Level, number> = {
@@ -50,6 +52,7 @@ export namespace Log {
   export function file() {
     return logpath
   }
+  let write: (msg: string) => void
 
   export async function init(options: Options) {
     if (options.level) level = options.level
@@ -62,7 +65,7 @@ export namespace Log {
     const logfile = Bun.file(logpath)
     await fs.truncate(logpath).catch(() => {})
     const writer = logfile.writer()
-    process.stderr.write = (msg) => {
+    write = (msg) => {
       writer.write(msg)
       writer.flush()
       return true
@@ -118,27 +121,31 @@ export namespace Log {
       const next = new Date()
       const diff = next.getTime() - last
       last = next.getTime()
-      return [next.toISOString().split(".")[0], "+" + diff + "ms", prefix, message].filter(Boolean).join(" ") + "\n"
+      return (
+        [next.toISOString().split(".")[0], "+" + diff + "ms", prefix, message]
+          .filter(Boolean)
+          .join(" ") + "\n"
+      )
     }
     const result: Logger = {
       debug(message?: any, extra?: Record<string, any>) {
         if (shouldLog("DEBUG")) {
-          process.stderr.write("DEBUG " + build(message, extra))
+          write("DEBUG " + build(message, extra))
         }
       },
       info(message?: any, extra?: Record<string, any>) {
         if (shouldLog("INFO")) {
-          process.stderr.write("INFO  " + build(message, extra))
+          write("INFO  " + build(message, extra))
         }
       },
       error(message?: any, extra?: Record<string, any>) {
         if (shouldLog("ERROR")) {
-          process.stderr.write("ERROR " + build(message, extra))
+          write("ERROR " + build(message, extra))
         }
       },
       warn(message?: any, extra?: Record<string, any>) {
         if (shouldLog("WARN")) {
-          process.stderr.write("WARN  " + build(message, extra))
+          write("WARN  " + build(message, extra))
         }
       },
       tag(key: string, value: string) {