consider simple cmake script below trying find fictional theheader.h c header file. far know, typical way locate include directory of library in findxxx.cmake modules.
cmake_minimum_required(version 2.6) project(test) find_path( test_includes names "theheader.h" ) message(status "test_includes: ${test_includes}") now assume that, in way unrelated cmake script, have edited path environment variable (i'm running linux) contain custom bin directory:
path="/home/cschreib/someapp/bin:$path" turns out, directory /home/cschreib/someapp/include exists, , contains file named theheader.h. header used locally build someapp, never meant used other programs*.
before cmake 3.3, custom location never found cmake. however, starting version 3.3, cmake tries smart , substitutes bin include directories in $path. therefore, cmake 3.3 (and above) find theheader.h in custom directory. because never intended, causing sorts of trouble, including mismatch between headers , shared objects versions.
i know can tell cmake not in $path using no_system_environment_path option in find_path, looking more generic solution issue. indeed, problem can happen library. make copy of findxxx.cmake modules need , systematically add no_system_environment_path option, rather avoid this.
is there global switch use turn off unwanted feature? or other way out?
*: before comments on this. aware not practice. aware that, in community, people tend not care , bad practices, , situation common. since not going change community, want cmake scripts robust against bad practices.
this behavior removed again non-windows platform cmake version 3.6.
if run problem update the latest cmake version. see version 3.6 release notes deprecated , removed features:
the
find_library(),find_path(), ,find_file()commands no longer search in installation prefixes derivedpathenvironment variable on non-windows platforms. behavior added in cmake 3.3 support windows hosts has proven problematic on unix hosts. users keep<prefix>/bindirectories in path tools not want supporting<prefix>/libdirectories searched. 1 may setcmake_prefix_pathenvironment variable ;-list of prefixes searched.
