[ben0x539]

I wasn't really thinking about language-level runtimes, like, I don't want to solve the problem of only having one global scope in python and running into module name collisions. I'm not sure how concerned rez is with shell environments beyond what (eg.) python packages are available in it, but I was wondering about having a shell where a program foo is available that, say, requires a lib compiled with gcc-4, and another program bar that requires the same lib at the same version but compiled with gcc-3.

Nix expends a bunch of complexity into fucking with dynamic linking to make that work transparently most of the time and deploying wrapper scripts to cover other cases, so I was curious if rez has a cleverer solution there.

[aprdm]

Oh yeah, it is certainly possible.

you have build_requires which you can list dependencies that you require at build time (e.g: gcc-3 vs gcc-4) but not at runtime.

So you can have things that were built with gcc-3 and gcc-4 running side by side in a same shell environment without issues.

gcc itself, in this case, would be a rez package that can have multiple versions installed in the system.