I recently updated to Xcode 12 on macOS 10.15.6. Xcode 12 comes with Apple Clang 12.0.0 (LLVM Clang 10.0.0), which fails to compile bash 5.0.18. This can be reproduced with the typical `./configure; make; make install` logic. The exact error message is:
In file included from siglist.c:36: In file included from ./xmalloc.h:25: In file included from ./bashansi.h:28: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/string.h:134:7: error: expected identifier or '(' char *strsignal(int __sig); ^ ./siglist.h:37:27: note: expanded from macro 'strsignal' # define strsignal(sig) (char *)sys_siglist[sig] ^ In file included from siglist.c:36: In file included from ./xmalloc.h:25: In file included from ./bashansi.h:28: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/string.h:134:7: error: expected ')' ./siglist.h:37:27: note: expanded from macro 'strsignal' # define strsignal(sig) (char *)sys_siglist[sig] ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/string.h:134:7: note: to match this '(' ./siglist.h:37:26: note: expanded from macro 'strsignal' # define strsignal(sig) (char *)sys_siglist[sig] ^ siglist.c:38:7: error: redefinition of 'sys_siglist' with a different type: 'char *[32]' vs 'const char *const [32]' char *sys_siglist[NSIG]; ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: previous declaration is here extern __const char *__const sys_siglist[NSIG]; ^ siglist.c:46:20: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[i] = (char *)0x0; ~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:48:18: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[0] = _("Bogus signal"); ~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:51:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGHUP] = _("Hangup"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:55:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGINT] = _("Interrupt"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:59:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGQUIT] = _("Quit"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:63:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGILL] = _("Illegal instruction"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:67:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGTRAP] = _("BPT trace/trap"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:75:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGABRT] = _("ABORT instruction"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:79:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGEMT] = _("EMT instruction"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:83:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGFPE] = _("Floating point exception"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:87:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGKILL] = _("Killed"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:91:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGBUS] = _("Bus error"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:95:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGSEGV] = _("Segmentation fault"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:99:23: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGSYS] = _("Bad system call"); ~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:103:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGPIPE] = _("Broken pipe"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ siglist.c:107:24: error: cannot assign to variable 'sys_siglist' with const-qualified type 'const char *const [32]' sys_siglist[SIGALRM] = _("Alarm clock"); ~~~~~~~~~~~~~~~~~~~~ ^ /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/signal.h:70:30: note: variable 'sys_siglist' declared const here extern __const char *__const sys_siglist[NSIG]; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ fatal error: too many errors emitted, stopping now [-ferror-limit=] 20 errors generated. make: *** [siglist.o] Error 1 I can share the full build log if you need it. Adam