https://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html says about the target rules:
.POSIX The application shall ensure that this special target is specified without prerequisites or commands. If it appears as the first non-comment line in the makefile, /make/ shall process the makefile as specified by this section; otherwise, the behavior of /make/ is unspecified. But even though one may add a .POSIX target as the first non-comment line in one's Makefile.am file, Automake will add various non-comment lines before this target in the generated Makefile. I received a remark about that for GNU MPFR. Though GNU make does not require this target to be the first non-comment line, this may matter with other make implementations. This could be done either by detecting a .POSIX target in Makefile.am or with some AM_* macro in the configure.ac file. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)