I wonder how this could be caught in CI. There is a test, but I guess we'd need separate ones to touch each Find* module, which is then just as easy to forget about as adding them to /Makefile.am.

Unless we can write a parser that figures out what modules we use and then check that they are all present...

You can create test that curl compile with other library/program (curl is a 3rd party) and check this things.

Similar to test, but test have different cmake that don't depends on curl cmake.

Here's an attempt to test this in CI (and locally with the -DENABLE_DIST_TEST=ON option): #14323

You can create test that curl compile with other library/program (curl is a 3rd party) and check this things.

sure, but then we would need to make builds (from a dist tarball) for all dependencies that use a cmake module

Maybe the bug can reproduce without the distro tar ball, with simple make install for curl and install dependencies with apt get or similar. Write other cmake that will try to find curl and it dependencies.

The tarball or building anything is unnecessary. I went with a CMake custom option that reads Makefile.am and checks if all on-disk .cmake/.in files are referenced from it.

I think we talking here about more errors that can be found with cmake builds and make them automatic.