rust: NetBSD 9 earmv7, version selection, RUST_TYPE

[Greg Troxel <gdt%lexort.com@localhost>]

(As usual I am pkg_rring on a variety of systems.)

I have an RPI3, running NetBSD/earmv7hf-el.  I set RUST_TYPE=bin (in
general, but on this machine, with "only" 1GB, rust has ~no hope of
building).

From having run pkgrr, I now have rust-bin-1.83.0 installed and it seems
to work.

Then, building libimagequant, I get:

  => Build dependency rust-bin>=1.56.1<1.77: NOT found
  => Verifying bin-install clean for ../../lang/rust176-bin
  ===> Binary install for rust-bin>=1.56.1<1.77
  => Becoming ``root'' to make su-do-bin-install (sudo)
  ERROR: rust-bin-1.83.0 is already installed - perhaps an older version?
  ERROR: If so, you may wish to ``pkg_delete rust-bin-1.83.0'' and install
  ERROR: this package again by ``/usr/bin/make bin-install'' to upgrade it properly.
  *** Error code 1

but libimagequant doesn't specify a version.

The "<1.77" is because of lang/rust/platform.mk

  .if ${MACHINE_PLATFORM:MNetBSD-*-earm*} && ${OPSYS_VERSION} < 100000
  RUST_DIR?=      ../../lang/rust176
  .endif
  RUST_DIR?=      ../../lang/rust

followed by rust.mk

  BUILDLINK_API_DEPENDS.rust-bin+=        rust-bin>=${RUST_REQ}

and lang/rust176-bin/buildlink3.mk

  BUILDLINK_API_DEPENDS.rust-bin+=        rust-bin>=1.56.1<1.77


In total, this is incorrect as rust-bin (1.83) installs fine and works.
There is no comment explaining the conditional and I'm guessing a build
of 1.83 from source fails, but that's me guessing.


I'm not sure what the right fix is, among:

  the 176 switch is obsolete and should be removed

  the 176 switch should be gated on RUST_TYPE being src

  rust176 bl3 should allow newer, but that breaks the property of
  actually wanting old rust, vs old rust being second best

  rust-bin 1.83.0 is actually broken on 9 earmv7 and shouldn't be
  allowed to be installed

  ?


I have commented out the .if locally, as I don't feel that I understand
rust enough to commit a change (in general, even if not freeze).  Now
libimagequant builds and packages, and it looks not particularly
troubled (it is building during the install phase, but I doubt that's
about 1.83).  The pkgrr is on to py312-maturin.