Build of testthat fails

[liheinz]

When I try to build the current master it fails with
`
../inst/include/testthat/vendor/catch.h:6495:33: error: size of array ‘altStackMem’ is not an integral constant-expression

6495 | static char altStackMem[SIGSTKSZ];

size of array ‘altStackMem’ is not an integral constant-expression

6546 | char FatalConditionHandler::altStackMem[SIGSTKSZ] = {};

`
With gcc version: 11.1.1

[liheinz]

glibc changed SIGSTKSZ to be a syscall instead
of being constant. #catchorg/Catch2#2178

[Enchufa2]

Yeap, this is failing in Fedora rawhide with the latest glibc version.

[gavinsimpson]

This just bit me today trying to get R 4.1 on Fedora (which is only available on rawhide currently) set up so that I could resolve all the changes that were made to testthat and vdiffr with the latest release. Compiling testhat from source there failed with the same issues as reported by @linusheinz and @Enchufa2

[clauswilke]

Any suggestions on how to fix this?

[Enchufa2]

Two options:

• Change SIGSTKSZ with some fixed value (this is the quick&dirty patch we have in place for now in Fedora). Not very elegant nor portable. Not sure if this could cause trouble in some architectures.
• Allocate the array dynamically with SIGSTKSZ, which is now a syscall. This is what many projects have been doing. See e.g. this.

[clauswilke]

Actually, looks like this has been fixed in the upstream code and it's just a matter of updating catch to the latest release: https://github.com/catchorg/Catch2/releases/tag/v2.13.5
(I'm linking to the release that has the fix. We're already one release past that.)

[Enchufa2]

Ah, I didn't realise it was vendored code. So that's it, you just need to update. :)

[jimhester]

Unfortunately it is not entirely trivial to update the Catch code, as the current code uses Catch1, not Catch2, which has some breaking changes. The most significant of which is that Catch2 requires full support for C++11.