From 426ecd7f5d7fdb64e9b5271aef6c08b6f474503f Mon Sep 17 00:00:00 2001
From: dgandhi62 <gandhidhyan@gmail.com>
Date: Fri, 25 Sep 2026 11:01:53 -0400
Subject: [PATCH 1/2] chore: add better error handling

---
 .../@aws-cdk-testing/cli-integ/lib/shell.ts     | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/packages/@aws-cdk-testing/cli-integ/lib/shell.ts b/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
index 0dacfe703..b5cbdcdf5 100644
--- a/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
+++ b/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
@@ -133,6 +133,23 @@ export async function shell(command: string[], options: ShellOptions = {}): Prom
 
       if (code === 0 || options.allowErrExit) {
         resolve(out);
+      } else if (code === 127) {
+        // Exit 127 is the shell's "command not found". It means the executable
+        // named in the command wasn't resolvable on PATH when this ran — NOT
+        // that the command itself did something wrong. This most often happens
+        // when the CLI-under-test isn't installed/on PATH, or when the test's
+        // environment has already been torn down (e.g. this shell ran after the
+        // test was killed on timeout). Surfacing that here keeps investigators
+        // from chasing the named command (e.g. `cdk synth`) instead of the real
+        // cause.
+        logAndReject(new Error(
+          `'${command.join(' ')}' exited with error code 127 (command not found): ` +
+          `'${command[0]}' was not resolvable on PATH when it ran. ` +
+          'This usually means the executable is not installed or not on PATH, ' +
+          'or the test environment was torn down before this command ran ' +
+          '(for example, after the test was killed on timeout) — not a defect in ' +
+          `'${command[0]}' itself.`,
+        ));
       } else {
         logAndReject(new Error(`'${command.join(' ')}' exited with error code ${code}.`));
       }

From ca49d9d0e9c2840656879e20f08fe79e5c02f1a3 Mon Sep 17 00:00:00 2001
From: dgandhi62 <gandhidhyan@gmail.com>
Date: Fri, 25 Sep 2026 11:10:57 -0400
Subject: [PATCH 2/2] fix(cli-integ): attribute exit code 127 as a missing
 executable

A command exiting 127 (POSIX 'command not found') was reported by shell()
as a bare 'exited with error code 127', which reads like the named command
(e.g. 'cdk synth') itself failed. In canary logs this sent investigators
toward CDK/synth instead of the real cause: an executable invoked by the
command was not on PATH when it ran.

Special-case exit code 127 to state what the failure points to (a missing
or unavailable executable) rather than a defect in the named command.
---
 .../@aws-cdk-testing/cli-integ/lib/shell.ts    | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/packages/@aws-cdk-testing/cli-integ/lib/shell.ts b/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
index b5cbdcdf5..0464b5e21 100644
--- a/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
+++ b/packages/@aws-cdk-testing/cli-integ/lib/shell.ts
@@ -134,21 +134,11 @@ export async function shell(command: string[], options: ShellOptions = {}): Prom
       if (code === 0 || options.allowErrExit) {
         resolve(out);
       } else if (code === 127) {
-        // Exit 127 is the shell's "command not found". It means the executable
-        // named in the command wasn't resolvable on PATH when this ran — NOT
-        // that the command itself did something wrong. This most often happens
-        // when the CLI-under-test isn't installed/on PATH, or when the test's
-        // environment has already been torn down (e.g. this shell ran after the
-        // test was killed on timeout). Surfacing that here keeps investigators
-        // from chasing the named command (e.g. `cdk synth`) instead of the real
-        // cause.
         logAndReject(new Error(
-          `'${command.join(' ')}' exited with error code 127 (command not found): ` +
-          `'${command[0]}' was not resolvable on PATH when it ran. ` +
-          'This usually means the executable is not installed or not on PATH, ' +
-          'or the test environment was torn down before this command ran ' +
-          '(for example, after the test was killed on timeout) — not a defect in ' +
-          `'${command[0]}' itself.`,
+          `'${command.join(' ')}' exited with error code 127. ` +
+          'An executable invoked by this command ' +
+          'was not found on PATH when it ran. This points to a missing or ' +
+          `unavailable executable, not to a failure within '${command[0]}' itself.`,
         ));
       } else {
         logAndReject(new Error(`'${command.join(' ')}' exited with error code ${code}.`));