[Bug c++/124542] New: [modules] internal compiler error: "error reporting routines re-entered" from recursive_lazy while testing <simd> in std module

[mkretz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124542

            Bug ID: 124542
           Summary: [modules] internal compiler error: "error reporting
                    routines re-entered" from recursive_lazy while testing
                    <simd> in std module
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mkretz at gcc dot gnu.org
  Target Milestone: ---

Created attachment 63947
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63947&action=edit
reduced -freport-bug output

I hit "internal compiler error: error reporting routines re-entered." when
testing in libstdc++ with

# GLIBCXX_TESTSUITE_STDS="modules" make check
RUNTESTFLAGS="conformance.exp=std/simd/arithmetic.cc"

The <simd> code is not yet merged to trunk, and I fear the attachment doesn't
help since the module binary is missing.