Re: Recently committed rust 1.54.0 update breaks building librsvg on AArch64

[Tobias Nygren <tnn%NetBSD.org@localhost>]

Something broken with aarch64 LSE atomic builtins in the rust toolchain.
It's not the "long double" problem (fp_mode.o) but similar with lse.o.
I have developed a workaround for librsvg.
Unless there are objections and people prefer a rust rollback (PMC?)
I can commit this after testing a few packages that depend on librsvg.

I think the problem is actually pretty easy to fix in rustc. It just
needs to stop adding lse.o multiple times to the archive. But it's
better to kludge-fix librsvg during the freeze.

--- graphics/librsvg/Makefile   20 Aug 2021 02:54:51 -0000      1.133
+++ graphics/librsvg/Makefile   23 Sep 2021 11:32:21 -0000
@@ -26,6 +26,18 @@ TEST_TARGET=         check

 .include "cargo-depends.mk"

+.include "../../mk/bsd.prefs.mk"
+
+# librsvg broken with rustc-1.54.0. Temp fix for pkgsrc freeze.
+.if !empty(MACHINE_PLATFORM:MNetBSD-*-aarch64)
+RUSTFLAGS+=    -C target-feature=-lse
+PKG_LIBTOOL=   ${WRKDIR}/libtool
+pre-configure:
+       sed 's,$$AR t "$$f_ex_an_ar_oldlib",& | grep -v lse.o,' \
+         < ${PREFIX}/bin/libtool > ${WRKDIR}/libtool
+       chmod +x ${WRKDIR}/libtool
+.endif