FYI, macOS has an old bison (version 2.3 from 2006). Installing the current version of bison (3.8.2) eliminated most of the yacc errors. Here's what I get now with 1.16j ... FAIL: t/aclocal-deleted-header-aclocal-amflags FAIL: t/aclocal-deleted-header FAIL: t/aclocal-deps FAIL: t/py-compile-basedir FAIL: t/subdir-add2-pr46 FAIL: t/yacc-mix-c-cxx In both aclocal-deleted-header.sh and aclocal-deleted-header-aclocal-amflags.sh, isn't an additional "$ACLOCAL -I . && $AUTOMAKE && $AUTOCONF && ./configure" needed before the second $MAKE? > On Jan 3, 2024, at 3:07 PM, Karl Berry wrote: > > Using am_cv_sleep_fractional_seconds=false dropped it to 7-11 tests failing. > > Erik, thanks for all the trials and detailed analysis. > Nothing is immediately clear to me either :(, but I'll take a look. -k