cli: synth fails if cdk.out does not exist

🐛 Bug Report

What is the problem?

cdk synth returns ENOENT: no such file or directory, open 'cdk.out/manifest.json' when the cdk.out directory is not present.

However, this results in the creation of a default manifest.json, and subsequent calls to synth succeed

Reproduction Steps

from cdk project directory:

1. mvn clean
2. rm -rf cdk.out
3. mvn compile
4. cdk synth

Verbose Log

xxxxxxxxx:cdk xxxxxxxx$ ls
cdk.json        cdk.out         pom.xml         src             target
xxxxxxxxx:cdk xxxxxxxx$ mvn clean
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< com.xxx.xxx:project >--------------------
[INFO] Building project 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ project ---
[INFO] Deleting /Users/xxxxxxxx/workspace/xxxxxxxx/cdk/target
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.303 s
[INFO] Finished at: 2019-08-19T16:27:07-07:00
[INFO] ------------------------------------------------------------------------
xxxxxxxxx:cdk xxxxxxxx$ rm -rf cdk.out
xxxxxxxxx:cdk xxxxxxxx$ mvn compile
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< com.xxx.xxx:project >--------------------
[INFO] Building project 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ project ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/xxxxxxxx/workspace/xxxxxxxx/cdk/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ project ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to /Users/xxxxxxxx/workspace/xxxxxxxx/cdk/target/classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.835 s
[INFO] Finished at: 2019-08-19T16:27:24-07:00
[INFO] ------------------------------------------------------------------------
xxxxxxxxx:cdk xxxxxxxx$ cdk synth
[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< com.xxx.xxx:project >--------------------
[INFO] Building project 0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- exec-maven-plugin:1.6.0:java (default-cli) @ project ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.574 s
[INFO] Finished at: 2019-08-19T16:27:31-07:00
[INFO] ------------------------------------------------------------------------
ENOENT: no such file or directory, open 'cdk.out/manifest.json'

Environment

• CDK CLI Version: 1.4.0 (build 175471f)
• Module Version:
• OS: OSX Mojave
• Language: Java

Other information

[nija-at]

Thanks to @ivoanjo who also had this problem, I’m able to reproduce this in Java.

I was able to reproduce this using our standard sample-app package from cdk init -l=java and modify the code to drop app.synth(). Running cdk synth on this when there’s no cdk.out/ folder gets this error.

There seems to be some race condition between the cdk.out/ folder being generated and when the CLI expects it to be present for parsing. This specifically happens when the app does not call app.synth().

For those encountering this issue, the workaround is for your app to call app.synth() at the end of the program.

[thekevinbrown]

For me the issue was that I had missed the difference between the file in bin and the file in lib, so I was missing:

const app = new cdk.App();
new MyStack(app, 'MyStack');

As soon as I added that back in I stopped getting the error about the missing file. It’d be great if we could improve the error message in this case.