Hello,

I am trying to port https://github.com/astral-sh/uv/
This is written with Rust.

Here is the WIP Makefile :

```
COMMENT =               Extremely fast Python package and project manager

GH_ACCOUNT =            astral-sh
GH_PROJECT =            uv
GH_TAGNAME =            0.7.19

CATEGORIES =            sysutils
HOMEPAGE =              https://github.com/astral-sh/uv

# MIT
PERMIT_PACKAGE =        Yes

WANTLIB =               ${MODCARGO_WANTLIB} m
MODULES =               devel/cargo
CONFIGURE_STYLE =       cargo

.include <crates.inc>
.include <bsd.port.mk>
```

I used `make modcargo-gen-crates > crates.inc` to generate crates.inc but when I
do make build, it tries to download an external dependency that seems to not be
managed by modcargo-gen-crates.

```
===>  Building for uv-0.7.19
error: failed to load source for dependency `reqwest-middleware`

Caused by:
  Unable to update
https://github.com/astral-sh/reqwest-middleware?rev=ad8b9d332d1773fde8b4cd008486de5973e0a3f8#ad8b9d33

Caused by:
  can't checkout from 'https://github.com/astral-sh/reqwest-middleware': you are
in the offline mode (--offline)
*** Error 101 in . (/usr/ports/devel/cargo/cargo.port.mk:369 'do-build': @cd
/usr/ports/pobj/uv-0.7.19/uv-0.7.19 && /usr/bin/env -i PORTSDIR...)
*** Error 2 in . (/usr/ports/infrastructure/mk/bsd.port.mk:3065
'/usr/ports/pobj/uv-0.7.19/.build_done': @cd /usr/ports/sysutils/uv && PKGPA...)
*** Error 2 in /usr/ports/sysutils/uv
(/usr/ports/infrastructure/mk/bsd.port.mk:2712 'build': @lock=uv-0.7.19;  export
_LOCKS_HELD=" uv-0.7....)
```

Is there some kind of option to download the dependency ? Should I add an
external source ?

Denis