depinst option to reject dependency cycles

[grisumbras]

Hopefully this will work better than the previous approach.

I had to split directories into main and extra, because otherwise tracking what comes from where becomes onerous.

[pdimov]

This looks good. But I don't want the stack trace. Catch the exception, print the message, and exit.

[pdimov]

I don't think that vprint(0 is what we want there, because (a) fatal errors should go to stderr and (b) they shouldn't be suppressed by -q.

[pdimov]

Perfect, thank you.

Unfortunately the print to stderr appears before the normal output in GHA's log:

Error: Dependency cycle detected: geometry -> graph -> geometry
Installing: config, headers, ../tools/boost_install, ../tools/build, ../tools/cmake, geometry
Installing: config, range, rational, concept_check, math, core, static_assert, iterator, numeric/conversion, endian, throw_exception, type_traits, predef, variant, graph, assert, algorithm, mpl, lexical_cast, tokenizer, tuple, container, serialization, integer, qvm, function_types, multiprecision, thread, array, variant2, fusion, any, polygon
Error: Process completed with exit code 1.

I tried sys.stdout.flush(), but it didn't help.

Any ideas how this could be fixed?

[grisumbras]

The only thing I can suggest is to add 2>&1 to the command.

[pdimov]

Yes, this output buffering seems to be a "feature" of Github Actions, there's nothing to be done from our side.

But I'm starting to think that vprint should have actually gone to stderr to begin with, as depinst doesn't print any "program output" per se, only status messages, which (one might argue) are stderr material.