While emerging this or that package, my portage occasionally fails to compile with multiple errors "env: php: No such file" but when I manually run make in the work directory the package usually compiles. I can't remember how many different packages I've encountered this. I'd rather emerge packages or @world without expecting I may have to cd to another work directory and finish the build.

Describing what specifically failed this time, after running emerge -auDN @world, media-libs/libmpeg2-0.5.1-r2 failed to emerge. After the autoconfigure and compilation of several modules, multiple lines "env: php: No such file or directory" appear, and make fails with Error 1. I do not have php installed; "which php" returns no php in my path.