Enable system-llvm for rust-1.18

[ambasta]

As per #37609, llvm 4 support has been merged into rust. It would be great to try out system-llvm with rust-1.18

[cnd]

@ambasta so far it's still being contributors driven 👍

[cnd]

good idea will be to try stuff from here https://github.com/smaeul/portage-overlay

[ambasta]

Well, that didn't work, so I spliced the ebuild here and in smaeul to https://github.com/ambasta/ambasta/blob/master/dev-lang/rust/rust-1.18.0.ebuild

Seems to work for me, though it does download the stage0 during build

[cnd]

@ambasta there are few things: use cargo or cargo-bin in PDEPEND add LLVM_MAX_SLOT (and maybe MIN), test if cargo builds fine with it, convert all spaces into tabs. https://github.com/ambasta/ambasta/blob/master/dev-lang/rust/rust-1.18.0.ebuild#L71 - this looks unneeded and maybe some other stage0 variables
https://github.com/ambasta/ambasta/blob/master/dev-lang/rust/rust-1.18.0.ebuild#L151 - rust-lldb should be added there
and maybe here too: https://github.com/ambasta/ambasta/blob/master/dev-lang/rust/rust-1.18.0.ebuild#L140
https://github.com/ambasta/ambasta/blob/master/dev-lang/rust/rust-1.18.0.ebuild#L86 - this variable is better be called llvm-prefix and ${EPREFIX} is no needed there I think

[ambasta]

@mpkh I removed the tabs before cat because I wanted to avoid tabs all together..

Will incorporate all the other recommendations :)

[cnd]

@amadio repoman (ebuild QA checker) is strongly against spaces in ebuild syntax

[ambasta]

You're right.. since my vim config automatically switches b/w tab and space mode(default space unless file has tabs), I'd assumed that I'd been using spaces all this time :(

[necrose99]

llvm-alt-0.5.0.ebuild.txt

cargo-ebuild , a number of rust add-ons for llvm in rust.. via cargo crates...

[cnd]

obsolete