Documenting my resolution to a build error caused when the brew update process upgraded me from libgccjit 11.3 to 12.1.

Error message from configure

============================

| checking for gcc_jit_context_acquire in -lgccjit... no

| configure: error: ELisp native compiler was requested, but libgccjit was not found.

| Please try installing libgccjit or a similar package.

| If you are sure you want Emacs be compiled without ELisp native compiler,

| pass the --without-native-compilation option to configure.

| make: *** [config.status] Error 1

config.log section showing linker can't map file

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

| configure:19555: checking for gcc_jit_context_acquire in -lgccjit

| configure:19578: gcc -o conftest -g3 -O2 -isystem /usr/local/Cellar/libffi/3.4.2/include -isystem /usr/local/Cellar/librsvg/2.54.4/include/librsvg-2.0 -isystem /usr/local/Cellar/gdk-pixbuf/2.42.8_1/include/gdk-pixbuf-2.0 -isystem /usr/local/Cellar/jpeg/9e/include -isystem /usr/local/Cellar/libtiff/4.4.0_1/include -isystem /usr/local/Cellar/glib/2.72.3/include -isystem /usr/local/Cellar/cairo/1.16.0_5/include/cairo -isystem /usr/local/Cellar/glib/2.72.3/include -isystem /usr/local/Cellar/glib/2.72.3/include/glib-2.0 -isystem /usr/local/Cellar/glib/2.72.3/lib/glib-2.0/include -isystem /usr/local/opt/gettext/include -isystem /usr/local/Cellar/pcre/8.45/include -isystem /usr/local/Cellar/pixman/0.40.0/include/pixman-1 -isystem /usr/local/Cellar/fontconfig/2.14.0/include -isystem /usr/local/opt/freetype/include/freetype2 -isystem /usr/local/Cellar/libpng/1.6.37/include/libpng16 -isystem /usr/local/Cellar/libxcb/1.15/include -isystem /usr/local/Cellar/libxrender/0.9.10/include -isystem /usr/local/Cellar/libxext/1.3.4/include -isystem /usr/local/Cellar/libx11/1.8.1/include -isystem /usr/local/Cellar/libxcb/1.15/include -isystem /usr/local/Cellar/libxau/1.0.9/include -isystem /usr/local/Cellar/libxdmcp/1.1.3/include -isystem /usr/local/Cellar/xorgproto/2022.1/include -isystem /usr/local/Cellar/webp/1.2.3_1/include -I/usr/local/Cellar/libgccjit/12.1.0/include conftest.c -lgccjit -lsqlite3 -L/usr/local/Cellar/libgccjit/12.1.0/lib/gcc/current

| /usr/local/Cellar/libgccjit/12.1.0/lib/gcc/12 >&5

| ld: warning: dylib (/usr/local/Cellar/libgccjit/12.1.0/lib/gcc/current/libgccjit.dylib) was built for newer macOS version (12.4) than being linked (12.0)

| ld: can't map file, errno=22 file '/usr/local/Cellar/libgccjit/12.1.0/lib/gcc/12' for architecture x86_64

| clang: error: linker command failed with exit code 1 (use -v to see invocation)

| configure:19578: $? = 1

configure.ac test for brew installed libgccjit

==============================================

In the example below the test in configure.ac returns two lines and

this appears to be the cause of the linker can't map file error.

| (python_training) bartm002@C02FM1E2MD6T ~ % brew ls -v libgccjit | grep -E 'libgccjit\.(so|dylib)$'

| /usr/local/Cellar/libgccjit/12.1.0/lib/gcc/current/libgccjit.dylib

| /usr/local/Cellar/libgccjit/12.1.0/lib/gcc/12/libgccjit.dylib

Here is the listing to show that both paths are really the same with

| /usr/local/Cellar/libgccjit/12.1.0/lib/gcc:

| drwxr-xr-x 4 bartm002 admin 128 May 6 00:53 .

| drwxr-xr-x 3 bartm002 admin 96 May 6 00:53 ..

| drwxr-xr-x 4 bartm002 admin 128 May 6 00:53 12

| lrwxr-xr-x 1 bartm002 admin 28 May 6 00:53 libgccjit.0.dylib -> ../current/libgccjit.0.dylib

| lrwxr-xr-x 1 bartm002 admin 26 May 6 00:53 libgccjit.dylib -> ../current/libgccjit.dylib

| drwxr-xr-x 4 bartm002 admin 128 May 6 00:53 current

| -rw-r--r-- 1 bartm002 admin 41M Aug 6 18:47 libgccjit.0.dylib

| lrwxr-xr-x 1 bartm002 admin 17 May 6 00:53 libgccjit.dylib -> libgccjit.0.dylib

Here I modify the test to return only the first line and the build

succeeds after this change.

| (python_training) bartm002@C02FM1E2MD6T ~ % brew ls -v libgccjit | grep -E 'libgccjit\.(so|dylib)$' | head -n 1

| /usr/local/Cellar/libgccjit/12.1.0/lib/gcc/current/libgccjit.dylib

| diff --git a/configure.ac b/configure.ac

| index 1a264275bd..2d88d0ac15 100644

| --- a/configure.ac

| +++ b/configure.ac

| @@ -4241,7 +4241,8 @@ AC_DEFUN

| MAC_CFLAGS="-I$(dirname $($BREW ls -v libgccjit | \

| grep libgccjit.h))"

| MAC_LIBS="-L$(dirname $($BREW ls -v libgccjit| \

| - grep -E 'libgccjit\.(so|dylib)$'))"

| + grep -E 'libgccjit\.(so|dylib)$'| \