As I mentioned the other day, I encountered a difficulty in building the documentation for the latest version of SBCL. That’s because I recently updated OS X to El Capitan, which has a new feature. It’s impossible for anyone (even root) to write into the /usr directory (/user/local is OK, though). That’s a bit annoying but I suppose it does make some sense from a security standpoint.
In any event, the MacTeX distribution used to set a symbolic link into /usr so that the shell and other applications could find the executables. Those links were removed when El Capitan was installed so the SBCL makefile couldn’t find TeX to build the documentation. It’s easy to fix this and Herbert Schulz has a nice writeup on how to do it. While I was at it I also downloaded and installed latest version of MacTeX. Once I had it loaded, I fixed my shell PATH variable and the SBCL documentation built without incident.
That left the problem of fixing the path variable in Emacs. That always seems much harder than it should. The reason is that the GUI version of Emacs under OS X does not import the PATH variable so you have to set it up by hand. Actually, you don’t. Steve Purcell has a tremendously useful package called exec-path-from-shell that imports the shell PATH variable into Emacs for you.
That simplifies everything. I just installed the package and it took care of telling Emacs where the TeX executables were. I highly recommend this package if you are an OS X user.