The “you broke the build!” game

time to read 2 min | 344 words

Recently I pulled some code from a colleague, and tried to test it. It worked, which was fine, so I let it run the tests, and went out to lunch.

When I came back, I was surprised to discover that the build has failed, not because of some test failing, but because it couldn’t compile. To be rather more exact, we go the following error:

 [optimized-build] Using type script compiler: C:\Program Files (x86)\Microsoft SDKs\TypeScript\1.4\tsc.exe
 [optimized-build] System.ComponentModel.Win32Exception thrown:
 [optimized-build] --------------------------
 [optimized-build] The filename or extension is too long
 [optimized-build] --------------------------

That was strange. I checked several times, and we had no such thing. No one had a veryVeryLongFileNameThatNeededToBeVeryExplicitAboutWhatItWasDoingAndDidNotCareAboutLength.ts.

And the tsc.exe location was in its normal place. This is from a part in our build process that gather all the TypeScript files and merge them into a single optimized bundle. And it suddenly failed. Now, on the colleague machine, it worked. The previous commit before I merged it, it worked. The merge was a clean one, and very obvious that nothing was going on there.

It took me a while, but I finally figured out that the error occurred because my colleague has added a new TypeScript file.

How can adding a file break the build?

As it turns out, the code we were calling did something like this:

tsc.exe file1.ts file2.ts file3.ts

And at some point, the size of the command line we were passing to the process has exceeded 32KB. And that is when everything broke loose.

Luckily, we were able to write those things to a file and ask the compiler to load them directly, instead of passing them via the command line:

tsc.exe @arguments.txt

And everything was okay again…