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Build errors look like this:

/builddir/build/BUILD/Catch2-1.12.2/include/internal/catch_fatal_condition.hpp:139:33: error: size of array 'altStackMem' is not an integral constant-expression
  139 |         static char altStackMem[SIGSTKSZ];
      |                                 ^~~~~~~~
/builddir/build/BUILD/Catch2-1.12.2/include/internal/catch_fatal_condition.hpp:191:45: error: size of array 'altStackMem' is not an integral constant-expression
  191 |     char FatalConditionHandler::altStackMem[SIGSTKSZ] = {};
      |                                             ^~~~~~~~

Fedora rawhide has a patch:

commit 059104ba87494c0b5ebe16844ec190f253e51cac
Author: Tom Hughes <tom>
Date:   Fri Feb 19 10:56:09 2021 +0000

    Add patch for non-constant SIGSTKSZ

But it is not entirely future-proof because 32 KiB may not be enough on future CPUs (although it should be good enough for AVX-512 support).