package/python-cryptography: needs cargo env when downloading

python-cryptography is a python package, but it internally builds a rust
crate. As such, it needs to be vendored at install time.

Currently, we only pass the path to the sub-directory where the rust
source is in the package tree, but calling cargo needs additional
variables, most notably it needs CARGO_HOME to be set in the
environment, otherwise it ends up writing in the user's own cargo home,
which is by default ~/.cargo/

We do not really know what variables are used at vendor time, so we pass
the full Cargo environment, that we pass when building target packages.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Asaf Kahlon <asafka7@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/python-cryptography/python-cryptography.mk

@@ -24,6 +24,7 @@ PYTHON_CRYPTOGRAPHY_ENV = \
 PYTHON_CRYPTOGRAPHY_DOWNLOAD_POST_PROCESS = cargo
 PYTHON_CRYPTOGRAPHY_DOWNLOAD_DEPENDENCIES = host-rustc
 PYTHON_CRYPTOGRAPHY_DL_ENV = \
+	$(PKG_CARGO_ENV) \
 	BR_CARGO_MANIFEST_PATH=src/rust/Cargo.toml
 
 $(eval $(python-package))