Diesel 1.4.x makes it impossible to properly cross-compile when using
PostgreSQL and thus having a dependency on libpq. On compile and I
believe when using the diesel_migrations crate, there is a dependency on
both the host and target libpq. Unfortunately, only one can be installed
at a time, because of conflicts. See also:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=995768
Until now the cross-compile solution is based on docker buildx, which
uses qemu to emulate the different targets. This works, but is very,
very slow.
Diesel 2.0.0-rc.0 no longer depends on both the host and target libpq on
compile and makes it possible to implement proper cross-compiling (using
the rust --target flag in combination with the cross-compile
toolchains).
