cargo install does not respect LDFLAGS

[ChrisMacNaughton]

When the building system has LDFLAGS set, cargo / rustc should respect the system's LDFLAGS

[alexcrichton]

Right now Cargo respects RUSTFLAGS but that's the only env var for passing flags down. What sort of LDFLAGS are you thinking of?

Note that the exact linker that the compiler invokes isn't guaranteed to not change over time, so there's not always a valid interpretation of LDFLAGS even if it exists.

[ChrisMacNaughton]

Sorry for the delay, @sergiusens would be able to go into more depth on the specifics. The goal was to get a Rust project built into a Snap with Snapcraft but the built binary wasn't using the correct libraries

[sergiusens]

where are RUSTFLAGS documented? The linker flags we want to pass on are runpath/rpath related as well as the one that sets the linker loader the binary should use.

[alexcrichton]

@sergiusens it's documented here

[ChrisMacNaughton]

expanding a bit on this, some issues we're having with getting this working: https://gist.github.com/ChrisMacNaughton/a81233e05995013ebb9a0c333c157b76