can't build rust -- out of swap space

[Yuri Pankov]

On 03.03.2020 11:49, Yuri Pankov wrote:
> With recent pkg fallout, I'm trying to build rust myself first time ever 
> (as far as I can remember), and it's failing running out of swap on the 
> following step:
> 
> Building stage0 std artifacts (x86_64-unknown-freebsd -> 
> x86_64-unknown-freebsd)
> running: 
> "/usr/ports/lang/rust/work/rustc-1.41.1-src/build/x86_64-unknown-freebsd/stage0/bin/cargo" 
> "build" "-Zconfig-profile" "--target" "x86_64-unknown-freebsd" 
> "-Zbinary-dep-depinfo" "-j" "1" "-v" "--release" "--frozen" "--features" 
> "panic-unwind backtrace compiler-builtins-c" "--manifest-path" 
> "/usr/ports/lang/rust/work/rustc-1.41.1-src/src/libtest/Cargo.toml" 
> "--message-format" "json-render-diagnostics"
> ^C^C^C
> Build completed unsuccessfully in 0:00:55
> 
> Here I pressed ^C as the build actually continues despite several 
> rustdoc, python, and other processes being killed.
> 
> swap_pager: out of swap space
> swp_pager_getswapspace(20): failed
> swap_pager: out of swap space
> swp_pager_getswapspace(11): failed
> 
> The system has 32G of RAM and 2GB swap partition (as advised by zfs-auto 
> installation option), top shows about 28G of memory free at that moment, 
> so I'm wondering why the swap is being used, and if 2G should be enough 
> to build rust.

Looks like I got this wrong, adding a file-backed swap space I was 
actually able to run top, and seeing only 100M of memory being "Free", 
~20G memory reported as "Active", and swap usage constantly growing 
being consumed by rustdoc process; something is really wrong here.

> Tried building both as root and user, DISABLE_MAKE_JOBS has no effect.