If I run the command foo specifying a a different libc to use as follows:
Is the globally defined libc used to run any of the command given above?
For the sake of context: consider the situation where your libc is physically present and accessible on your machine, but cannot be used for some reason. Given a logged in shell, in order to execute a specific command, you would need to provide a different libc.
LD_LIBRARY_PATH inline, would set it to the location of a working libc without apparent need to call the globally defined one.
Would the globally defined libc be called all the same in order to define locally the new environment variable?