Unable to Upgrade "librsvg" on Lion -- Needs "rust" Which Only Builds on Yosemite or Later!

[RobK88]

I am trying to upgrade librsvg on an old Mac running Lion. But the upgrade fails since rust is NOW needed and rust can only be built on Macs running Yosemite or later.

This bug looks similar to #62614

sudo port upgrade  librsvg
--->  Computing dependencies for rust
--->  Fetching distfiles for rust
Error: rust is only supported on macOS 10.10 or later.
Error: Failed to fetch rust: unsupported platform version
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_rust/rust/main.log for details.
Error: Problem while installing rust
Error: Follow https://guide.macports.org/#project.tickets to report a bug.

[RobK88]

Here is the strange part! Macports shows that the latest version of librsvg is already installed!

$ port info librsvg
librsvg @2.40.20_4 (graphics, gnome)
Variants:             quartz, universal, viewer, x11

Description:          GNOME implementation of rsvg.
Homepage:             https://wiki.gnome.org/Projects/LibRsvg

Extract Dependencies: xz
Build Dependencies:   pkgconfig
Library Dependencies: glib2, cairo, pango, gdk-pixbuf2, libxml2, vala, libcroco, gobject-introspection
Runtime Dependencies: python38
Platforms:            darwin
License:              (GPL-2+ or LGPL-2+)
Maintainers:          Email: devans@macports.org, GitHub: dbevans
                      Policy: openmaintainer

$ port installed librsvg
The following ports are currently installed:
  librsvg @2.40.20_4 (active)

[RobK88]

You can close this ticket.

librsvg must depend on libheif. Once I applied Marcus's proposed fix to libheif, I was able to run "sudo port upgrade librsvg" successfully.

So this bug will disappear once libheif is fixed. See #62614

[kencu (Ken)]

only the newer version of librsvg depends on rust; we use a held-back pre-rust version for all the older systems.

Something must be messed up.

[RobK88]

librsvg depends on libheif. See below.

$ port  rdependents libheif
The following ports are dependent on libheif:
  gd2
    graphviz
      vala
        librsvg
          adwaita-icon-theme

So once libheif gets fixed, librsvg will compile again.

I can confirm that this is the case. Once I was able to compile and install the latest version of libheif after applying Marcus's proposed fix, I was able to compile and install the latest version of librsvg without any issues.

[ryandesign (Ryan Carsten Schmidt)]

Duplicate of #62614.