Makefile.am:5: warning: user variable 'GZIP_ENV' defined here ...
/usr/share/automake-1.14/am/distdir.am: ... overrides Automake variable 'GZIP_ENV' defined here
Makefile.am:58: warning: user target 'distcleancheck' defined here ...
/usr/share/automake-1.14/am/distdir.am: ... overrides Automake target 'distcleancheck' defined here
src/Makefile.am:459: warning: user target '.mm.o' defined here ...
/usr/share/automake-1.14/am/depend2.am: ... overrides Automake target '.mm.o' defined here
解决方法 发现
https://github.com/bitcoin/bitcoin/pull/11013
结论：历史遗留问题？可忽略的错误提示