Building swift on aws codebuild

Hey :wave:,
So I currently build my aws lambdas using swift on aws codebuild within a CI/CD pipeline. Works great so far. Now I'd like to add caching to codebuild to reduce the build times.
I configured codebuild to use an S3 bucket for caching the .build folder. Every new build runs on a entirely new machine and therefore the paths are different. I get the following error:

swift build --product LambdaName -c release --build-path /codebuild/output/src409372700/src/.build/build-LambdaName
33  [1/863] Compiling CSotoExpat xmltok_impl.c
34  [2/863] Compiling CSotoExpat xmltok_ns.c
35  [3/865] Compiling INIParser INIParser.swift
36  <unknown>:0: error: PCH was compiled with module cache path '.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB', but the path is currently '/codebuild/output/src409372700/src/.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB'
37  <unknown>:0: error: missing required module 'SwiftShims'
38  [4/865] Compiling Logging Locks.swift
39  <unknown>:0: error: PCH was compiled with module cache path '.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB', but the path is currently '/codebuild/output/src409372700/src/.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB'
40  <unknown>:0: error: missing required module 'SwiftShims'
36  <unknown>:0: error: PCH was compiled with module cache path '.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB', but the path is currently '/codebuild/output/src409372700/src/.build/build-LambdaName/x86_64-unknown-linux-gnu/release/ModuleCache/1LD7OVICEM9JB'

All google results on that topic suggest cleaning the derrived data folder of Xcode which is obviously not the case here.
How can I run swift build with changing paths to make use of the cache to reduce build times. Especially when the code did not change much.

Any help us much appreciated!
Thanks!

1 Like

Moved this to 'Using Swift' since it's not about working on the toolchain but about how to use the existing tooling to get the desired behavior.

Hello, did you find any solution?