Collecting build artifacts from subfolders

[mkl...@gmail.com]

Hi!

Somehow, I can't get my multi-directory build setup to work properly.

I have a Tupfile in the src/client directory which creates a file src/client/build/index.js:

: *.ts |> npx esbuild index.ts --bundle --outdir=build |> build/index.js

Togetether with several other build aritfacts, I'd like to collect this in my global Tupfile (sitting in the project's root directory) as such:

: src/client/build/index.js |> cp %f %o |> build/static/%b

Now, I get the following error:

tup error: Explicitly named file 'src/client/build/index.js' can't be listed as an input because it was generated from external directory 'src/client' - try placing the file in a group instead and using the group as an input.

Being not familiar with the <group> syntax, I unsuccesfully tried several variants, and I'm in need of a little help here.

(Or mybe I'm misunderstanding tup's capabilities.)

Regards,
Matthias