fix(workflows): resolve bash via absolute path on Windows (#1326)

.gitignore

@@ -105,3 +105,6 @@ packages/server/.env
 skills-lock.json
 test-results/
 .archon/ralph/
+
+# Atlas Intelligence local — 1Password-backed .env template (not for upstream)
+.env.template

packages/git/src/exec.ts

@@ -4,6 +4,29 @@ import { promisify } from 'util';
 
 const promisifiedExecFile = promisify(execFile);
 
+/**
+ * Resolve the bash binary path in a platform-aware way.
+ *
+ * On Windows, CreateProcess searches the System32 directory BEFORE the PATH
+ * env var. Bare `spawn('bash', ...)` therefore resolves to
+ * `C:\Windows\System32\bash.exe` (the WSL launcher), whose bash has broken
+ * `${VAR}` expansion when invoked in `-c` mode and uses `/mnt/c/` path
+ * convention instead of `/c/`. Both break workflow bash nodes.
+ *
+ * Fix: on Windows, default to the Git Bash absolute path. Overridable via
+ * ARCHON_BASH_PATH for non-standard Git installs (e.g. user-scope installer
+ * at %LOCALAPPDATA%\Programs\Git\bin\bash.exe).
+ *
+ * See: coleam00/Archon#1326
+ */
+export function resolveBashPath(): string {
+  if (process.env.ARCHON_BASH_PATH) return process.env.ARCHON_BASH_PATH;
+  if (process.platform === 'win32') {
+    return 'C:\\Program Files\\Git\\bin\\bash.exe';
+  }
+  return 'bash';
+}
+
 /** Wrapper around child_process.execFile for test mockability */
 export async function execFileAsync(
   cmd: string,

packages/git/src/index.ts

@@ -11,7 +11,7 @@ export type {
 export { toRepoPath, toBranchName, toWorktreePath } from './types';
 
 // Process and filesystem wrappers
-export { execFileAsync, mkdirAsync } from './exec';
+export { execFileAsync, mkdirAsync, resolveBashPath } from './exec';
 
 // Worktree operations
 export {

packages/workflows/src/dag-executor.ts

@@ -7,7 +7,7 @@
  */
 import { readFile } from 'fs/promises';
 import { resolve, isAbsolute } from 'path';
-import { execFileAsync } from '@archon/git';
+import { execFileAsync, resolveBashPath } from '@archon/git';
 import { discoverScripts } from './script-discovery';
 import type {
   WorkflowAssistantOptions,
@@ -1359,7 +1359,7 @@ async function executeBashNode(
   const timeout = node.timeout ?? SUBPROCESS_DEFAULT_TIMEOUT;
 
   try {
-    const { stdout, stderr } = await execFileAsync('bash', ['-c', finalScript], {
+    const { stdout, stderr } = await execFileAsync(resolveBashPath(), ['-c', finalScript], {
       cwd,
       timeout,
     });
@@ -2018,7 +2018,7 @@ async function executeLoopNode(
           nodeOutputs,
           true // escapedForBash
         );
-        await execFileAsync('bash', ['-c', substitutedBash], { cwd });
+        await execFileAsync(resolveBashPath(), ['-c', substitutedBash], { cwd });
         bashComplete = true; // exit 0 = complete
       } catch (e) {
         const bashErr = e as NodeJS.ErrnoException;