Hi, ----- On 13 Aug, 2019, at 05:01, Ken Cunningham ken.cunningham.web...@gmail.com wrote:
> Compilers like clang are prebuilt to search first in /usr/local for include > files and libraries, and then after that in /usr (or -isysroot). > > SO -- if you have things installed in /usr/local then those headers and > libraries will be found automatically and, helpfully, USED. > > THIS is why people love HomeBrew so much -- things seem to "just work" > because > they are installed (or symlinked) into /usr/local. > > However, this is also why things break cryptically without being able to > figure > out what the heck is going on. Because headers in /usr/local are being used > instead of the ones you thought would be used. > > IF you are very very clever, and can keep track of all this, you can use > multiple different systems together successfully. To re-iterate on this, if you really really want to keep things in /usr/local, make it a habit of doing all your port operations with the `-t` flag to enable trace mode (see https://trac.macports.org/wiki/FAQ#buildfails, point 4). Trace mode will make a best effort to hide files in /usr/local (and other locations that shouldn't exist on a "clean" system) from the build. Your builds will be slower, but they will be less likely to fail. -- Clemens Lang
