Strange error running `spago bundle-app` on v0.15


I’m upgrading a codebase to PureScript v0.15.4. I’ve managed to get things building cleanly after updating the FFI implementations to ES6 modules. However, when I run spago build-app, I get the following rather obscure error:

% spago bundle-app                                     
[info] Build succeeded.
Invalid argument `output/*/*.js'

Usage: purs COMMAND

  The PureScript compiler and tools
[error] Bundle failed.

Any thoughts on what might be going on here?

many thanks,


did you update spago as well?
I’m not sure but I think you use a version of spago that tries to use the compiler to bundle the app (from output) but that feature of the compiler was deprecated.

Newer versions of spago should use esbuild by default to do this instead.

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Ah, that makes sense (given the error message). I’ve upgraded spago to 0.20.8 and installed esbuild, and now I’m onto other problems, so it looks like this one is resolved. Thank you!