Symptom

New Apple Clang (shipped with recent Xcode / CLT updates) introduced the -Wnontrivial-memcall diagnostic, which rejects memset calls whose first argument is a pointer to a non-trivially copyable C++ type. Because WiredTiger compiles with -Werror, clean builds on macOS now fail with:

error: first argument in call to 'memset' is a pointer to non-trivially copyable type 'WT_BM'

Affected file

test/catch2/misc_tests/test_reconciliation_tracking.cpp, lines 40, 43, 46 — three memset calls on WT_BM, WT_BTREE, and WT_DATA_HANDLE.

Root cause

Apple Clang added -Wnontrivial-memcall to flag potentially unsafe memset / memcpy usage on types with non-trivial copy semantics. The three types in the test helper setup_failing_bm() are C structs with C++ wrappers that are considered non-trivially copyable by the new compiler version.

Fix

Cast the first argument to void * to suppress the diagnostic (standard practice; the zeroing is intentional and safe here):

// Before
memset(bm, 0, sizeof(*bm));
memset(btree, 0, sizeof(*btree));
memset(dhandle, 0, sizeof(*dhandle));

// After
memset((void *)bm, 0, sizeof(*bm));
memset((void *)btree, 0, sizeof(*btree));
memset((void *)dhandle, 0, sizeof(*dhandle));

Repro

Run wb (or cmake --build) on macOS with a recent Apple Clang toolchain. The error appears on a clean build.