Can't find OpenSSL on Ubuntu, with cross

[Crell]

I'm trying to build a (so far) toy-level project on (K)Ubuntu 20.04. The libssl-dev apt package is installed. My command:

cross run

Relevant output:

  run pkg_config fail: "`\"pkg-config\" \"--libs\" \"--cflags\" \"openssl\"` did not exit successfully: exit code: 1\n--- stderr\nPackage openssl was not found in the pkg-config search path.\nPerhaps you should add the directory containing `openssl.pc\'\nto the PKG_CONFIG_PATH environment variable\nNo package \'openssl\' found\n"

  --- stderr
  thread 'main' panicked at '

  Could not find directory of OpenSSL installation, and this `-sys` crate cannot
  proceed without this knowledge. If OpenSSL is installed and this crate had
  trouble finding it,  you can set the `OPENSSL_DIR` environment variable for the
  compilation process.

  Make sure you also have the development packages of openssl installed.
  For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.

  If you're in a situation where you think the directory *should* be found
  automatically, please open a bug at https://github.com/sfackler/rust-openssl
  and include information about your system as well as this message.

  $HOST = x86_64-unknown-linux-gnu
  $TARGET = x86_64-unknown-linux-gnu
  openssl-sys = 0.9.58

  ', /cargo/registry/src/github.com-1ecc6299db9ec823/openssl-sys-0.9.58/build/find_normal.rs:157:5
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...
error: build failed

Googling the error message suggested setting a PCK_CONFIG_PATH env var manually, like so:

PKG_CONFIG_PATH="/usr/lib/x86_64-linux-gnu/pkgconfig/" cross run

But that gave the same error. I have confirmed that /usr/lib/x86_64-linux-gnu/pkgconfig/openssl.pc does exist.

cargo build does not give the same error. (I get a totally unrelated error in my own code, indicating it got through all of the dependencies successfully.)

[sfackler]

I'm not familiar with cross, but it seems like it may not be propagating environment variables through to cargo or something like that. You'd probably be best off asking them.

[Crell]

It's this thing: https://github.com/rust-embedded/cross

And a search there suggests it may be related to this:
cross-rs/cross#404

[sfackler]

Closing in favor of that issue.