Relevant changes see ChangeLog for details:
Add support for ${.SUFFIXES} as read-only variable.
Fix memory leak in cond.c
Punt on write errors - ENOSPC etc.
Lots of code refactoring, rework to reduce memory allocations.
More unit-tests.
From ChangeLog
* VERSION: 20180222
Merge with NetBSD make, pick up
o parse.c: avoid calling sysconf for every call to loadfile
* VERSION: 20180218
Merge with NetBSD make, pick up
o var.c: Var_Set handle NULL value anytime.
* VERSION: 20180212
Merge with NetBSD make, pick up
o parse.c: do not treat .info as warning with -W
* VERSION: 20171207
Merge with NetBSD make, pick up
o var.c: Var_Append use Var_Set if var not previously set
so that VAR_CMD is handled correctly.
Add a suitable unit-test.
* VERSION: 20171126
* aclocal.m4: use AC_LINK_IFELSE for AC_C___ATTRIBUTE__
since AC_TRY_COMPILE puts input inside main()
which upsets modern compilers.
* VERSION: 20171118
Merge with NetBSD make, pick up
o var.c: do not append to variable set on command line
add unit-test to catch this.
Interesting changes (from ChangeLog):
o meta.c: ignore paths that match .MAKE.META.IGNORE_PATTERNS
this is useful for gcov builds.
o propagate errors from filemon(4).
o meta.c: apply realpath() before matching against metaIgnorePaths
o allow makefile to set .MAKE.JOBS
