Attempt to fix macOS workflow mk7

.github/workflows/macos.yml

@@ -23,8 +23,8 @@ jobs:
       # /usr/local because macOS already provides this software.
       run: |
         brew install gperf bison flex
-        echo 'export PATH="/usr/local/opt/bison/bin:/usr/local/opt/flex/bin:$PATH"' >> /Users/runner/.bash_profile
-        export PATH="/usr/local/opt/bison/bin:/usr/local/opt/flex/bin:$PATH"
+        sudo ln -s /usr/local/opt/bison/bin/bison /usr/local/bin/bison
+        sudo ln -s /usr/local/opt/flex/bin/flex /usr/local/bin/flex
 
     - name: Install libinotify-kqueue
       # brew does not have libinotify package

src/Makefile.am

@@ -163,6 +163,8 @@ EXTRA_DIST = \
 # to the particular target name, so a header file name.
 $(LEXER_SRC:.l=.h): $(LEXER_SRC)
 	$(LEX) --header-file=$@ --stdout $(@:.h=.l) > /dev/null
+	$(YACC) --version
+	which $(YACC)
 
 # Anything built by make should be cleaned by make clean, but when it comes to
 # flex/bison automake's support leaves something to be desired