Build of testthat fails #1373
Description
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