No, this is just bad. The whole paradigm of having build setup depend on local variables in an interactive shell (which is pervasive, virtualenv is hardly the only bad actor here) is just broken inherently. It's lazy programming. It creates all sorts of failure modes -- builds can magically stop working when people update their .bashrc files (e.g. set PATH explicitly, but OOPS the build system expects to source a script and then spawn you an interactive shell), etc...
Implicit configuration is bad, OK? Just don't do it.
No, this is just bad. The whole paradigm of having build setup depend on local variables in an interactive shell (which is pervasive, virtualenv is hardly the only bad actor here) is just broken inherently. It's lazy programming. It creates all sorts of failure modes -- builds can magically stop working when people update their .bashrc files (e.g. set PATH explicitly, but OOPS the build system expects to source a script and then spawn you an interactive shell), etc...
Implicit configuration is bad, OK? Just don't do it.