subprocess maintenance

gadget-drone/src/gadget-drone.ts

@@ -696,6 +696,11 @@ class GadgetDrone extends GadgetProcess {
       process.exit(exitCode);
     });
 
+    process.on("uncaughtException", (error) => {
+      this.log.fatal("uncaught exception", { err: error });
+      process.exit(1);
+    });
+
     process.on("warning", (error) => {
       if (error.name === "DeprecationWarning") return;
       this.log.alert("warning", { error });

gadget-drone/src/services/subprocess.ts

@@ -2,8 +2,6 @@
 // Copyright (C) 2026 Rob Colbert <rob.colbert@openplatform.us>
 // Licensed under the Apache License, Version 2.0
 
-import assert from "node:assert";
-
 import path from "node:path";
 import fs from "node:fs";
 
@@ -63,17 +61,24 @@ class SubProcessService extends GadgetService {
     args?: string[],
   ): Promise<SubProcess> {
     const NOW = new Date();
-    assert(
+    const gadgetDir = WorkspaceService.gadgetDir;
-      WorkspaceService.gadgetDir,
+    if (!gadgetDir) {
-      "Gadget workspace directory not initialized",
+      throw new Error("Gadget workspace directory not initialized");
-    );
+    }
 
-    const logDir = path.join(WorkspaceService.gadgetDir, "subprocess-logs");
+    const logDir = path.join(gadgetDir, "subprocess-logs");
     await fs.promises.mkdir(logDir, { recursive: true });
 
     const projectDir = WorkspaceService.getProjectDirectory(project.slug);
-    const child = spawn(cmd, args, { cwd: projectDir });
+    const spawnArgs = args ?? [];
-    assert(child.pid, "subprocess did not define a process id");
+    const useShell = spawnArgs.length === 0;
+    const child = spawn(cmd, spawnArgs, { cwd: projectDir, shell: useShell });
+    child.on("error", (err) => {
+      this.log.error("subprocess spawn failed", { cmd, args, error: err.message });
+    });
+    if (!child.pid) {
+      throw new Error("Failed to spawn subprocess: child process has no pid");
+    }
 
     const pid = child.pid;
     const stdoutFileName = path.join(logDir, `subproc-${pid}.stdout.log`);

gadget-drone/src/tools/system/subprocess.ts

@@ -45,7 +45,7 @@ export class SubprocessTool extends GadgetTool {
             command: {
               type: "string",
               description:
-                "The shell command to execute (required for cmd=create). Example: 'node', 'npm', 'python', './my-server'.",
+                "The full shell command to execute (required for cmd=create). Examples: 'npm run dev', 'pnpm dev:frontend', 'node server.js'. The command is executed via /bin/sh.",
             },
             args: {
               type: "array",
@@ -128,7 +128,7 @@ export class SubprocessTool extends GadgetTool {
         message: "The 'command' parameter is required for cmd=create.",
         parameter: "command",
         recoveryHint:
-          "Provide the command to execute, e.g. 'node', 'npm', 'python'.",
+          "Provide the full command string to execute, e.g. 'npm run dev', 'pnpm dev:frontend'. The command is executed via /bin/sh.",
       });
     }
 
@@ -168,7 +168,7 @@ export class SubprocessTool extends GadgetTool {
       });
       return formatError({
         code: "OPERATION_FAILED",
-        message: `Failed to spawn subprocess: ${message}`,
+        message: `Failed to spawn subprocess: ${message}. Make sure the command is installed and available in PATH, or use the full path to the executable.`,
       });
     }
   }