Re: [gentoo-user] How to switch from rust to rust-bin?

[Dale]

Walter Dnes wrote:
>   When updating my refurbished Lenovo notebook, I saw that "rust" was
> being pulled in as a dependency by system-bootstrap.  My initial
> reaction was WTF?  I'm sure the kernel devs will say "because we said
> so... neener... neener".  I don't want to fight that argument.
>
>   Just like Mozilla's other product, rust is an unbelievably bloated
> monstrosity.  My 3-gig RAM notebook, with a core2 cpu forced to max
> (2.534 ghz) took 3 hours 51 minutes to build rust-1.45.2... ouch!  This
> compares to 2 hours 10 minutes for gcc-9.3, and 13 minutes for x265-3.4.
>
>   I notice that there is a "rust-bin" ebuild present.  If nothing else,
> I'd like to switch over to that to save the notebook from unnecessary
> grinding when rust updates.  What's the procedure for selecting it?
> I've already tried the obvious...
>
> [thimk][root][~] eselect rust list
> Available Rust versions:
>   [1]   rust-1.45.2 *
>
>
>   "emerge -pv rust-bin" gives...
>
> [ebuild  N     ] dev-lang/rust-bin-1.45.2:stable::gentoo  USE="-clippy -doc -rls -rustfmt" CPU_FLAGS_X86="sse2" 115,367 KiB
>
>   I *HOPE* that it's as simple as emerging rust-bin, and eselect-ing
> it, but I want to check here before I risk breaking my system with
> wild guesses.
>


It seems rust has a virtual package.  This is from eix:


[I] virtual/rust
     Available versions:  1.44.1{tbz2} ~1.45.2 ~1.46.0 {ABI_MIPS="n32
n64 o32" ABI_RISCV="lp64 lp64d" ABI_S390="32 64" ABI_X86="32 64 x32"}
     Installed versions:  1.44.1{tbz2}(11:53:29 PM
08/30/2020)(ABI_MIPS="-n32 -n64 -o32" ABI_RISCV="-lp64 -lp64d"
ABI_S390="-32 -64" ABI_X86="32 64 -x32")
     Description:         Virtual for Rust language compiler


According to the ebuild for the virtual, either the compile local
version or the -bin version satisfies the requirement.  From the virtual
ebuild.


RDEPEND="|| ( ~dev-lang/rust-${PV}[${MULTILIB_USEDEP}]
~dev-lang/rust-bin-${PV}[${MULTILIB_USEDEP}] )"


I'd think it would be as simple as unemerging the local compile version
and emerging the -bin version.  If unsure, quickpkg the version you have
installed now and save it in case you need it.  You may want to check
the ebuild for the package that is pulling it in and make sure it
depends on the virtual instead of the actual rust package itself.  It
could be it requires a locally compiled version and using a -bin version
isn't allowed for some reason.  I don't recall seeing a case like that
before but one never knows.  If it fails tho, you can just emerge your
saved binary using -k and not have to compile it again. 

Hope that gives you something to check into and helps. 

Dale

:-)  :-)