Empty main fails to link when using optimizations

[wackywendell]

Here is an example. This started about 3 days ago (approximately Jun 23).

This is a transcript:

Error: linking with `cc` failed: exit code: 1
note: cc '-m64' '-L' '/usr/lib64/rustlib/x86_64-unknown-linux-gnu/lib' '-o' 'out' 'out.o' '-lmorestack' '-nodefaultlibs' '-Wl,--gc-sections' '-Wl,--as-needed' '-Wl,-O1' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-59beb4f7-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/librand-2ea8f361-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libsync-305341d2-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustrt-d8560cb2-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcollections-d412c0c4-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-1085c790-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-4f9a876d-0.11.0-pre.rlib' '/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-c5ed6fb4-0.11.0-pre.rlib' '-L' '/home/rust/.rust' '-L' '/home/rust' '-Wl,-Bdynamic' '-ldl' '-lpthread' '-lgcc_s' '-lpthread' '-lc' '-lm' '-Wl,-rpath,$ORIGIN/../../usr/lib/rustlib/x86_64-unknown-linux-gnu/lib' '-Wl,-rpath,/usr/lib64/rustlib/x86_64-unknown-linux-gnu/lib' '-lcompiler-rt'
note: /usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o): In function `io::helper_thread::imp::new::h0d2a4e4166f99e80Aga::v0.11.0.pre':
(.text._ZN2io13helper_thread3imp3new20h0d2a4e4166f99e80Aga11v0.11.0.preE+0x20): undefined reference to `__morestack'
/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o): In function `io::helper_thread::imp::signal::h26ab199be3006ab7Vga::v0.11.0.pre':
(.text._ZN2io13helper_thread3imp6signal20h26ab199be3006ab7Vga11v0.11.0.preE+0x20): undefined reference to `__morestack'
/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o): In function `io::file::FileDesc::inner_write::h6a6d7310ccbe3c7czuc::v0.11.0.pre':
(.text._ZN2io4file8FileDesc11inner_write20h6a6d7310ccbe3c7czuc11v0.11.0.preE+0x20): undefined reference to `__morestack'
/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o): In function `io::file::FileDesc::new::h7d4e6e7953140ef49sc::v0.11.0.pre':
(.text._ZN2io4file8FileDesc3new20h7d4e6e7953140ef49sc11v0.11.0.preE+0x20): undefined reference to `__morestack'
/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o): In function `io..file..FileDesc::glue_drop.4666::h79789ec73bd99e31':
(.text._ZN18io..file..FileDesc14glue_drop.466617h79789ec73bd99e31E+0x20): undefined reference to `__morestack'
/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/libnative-1fb5e2c0-0.11.0-pre.rlib(native.o):(.text._ZN2io8addrinfo18GetAddrInfoRequest3run20hb725453b9f360021Kha11v0.11.0.preE+0x28): more undefined references to `__morestack' follow
collect2: error: ld returned 1 exit status

error: aborting due to previous error

[schmee]

Looks like a dupe of #15108, and should have been fixed in #15126. What version are you using?

[huonw]

@schmee it was the rustc that the playpen was using 8 hours ago.

The code now works, so I assume the playpen rustc recently updated to include that patch. Closing (thanks for noticing @schmee).