Test failure - src/test/debuginfo/nil-enum.rs

[daym]

We get a test failure using gdb 8.2:

------------------------------------------
NOTE: compiletest thinks it is using GDB version 8002000
executing "/gnu/store/vmfyql60lbji2ca50r2xd3sq1m41qrrl-gdb-8.2/bin/gdb" "-quiet"
 "-batch" "-nx" "-command=/tmp/guix-build-rust-1.25.0.drv-0/rustc-1.25.0-src/bui
ld/x86_64-unknown-linux-gnu/test/debuginfo/nil-enum.debugger.script"
------stdout------------------------------
GNU gdb (GDB) 8.2
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
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Breakpoint 1 at 0x11d2: file /tmp/guix-build-rust-1.25.0.drv-0/rustc-1.25.0-src/src/test/debuginfo/nil-enum.rs, line 41.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/gnu/store/l4lr0f5cjd0nbsaaf8b5dmcw1a1yypr3-glibc-2.27/lib/libthread_db.so.1".

Breakpoint 1, nil_enum::main () at /tmp/guix-build-rust-1.25.0.drv-0/rustc-1.25.0-src/src/test/debuginfo/nil-enum.rs:41
41              zzz(); // #break
$1 = nil_enum::ANilEnum
$2 = nil_enum::AnotherNilEnum
A debugging session is active.

        Inferior 1 [process 5860] will be killed.

Quit anyway? (y or n) [answered Y; input not from terminal]

------stderr------------------------------

------------------------------------------

error: line not found in debugger output: $1 = <error reading variable>
status: exit code: 0
...
thread '[debuginfo-gdb] debuginfo/nil-enum.rs' panicked at 'explicit panic', too
ls/compiletest/src/runtest.rs:2891:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.


failures:
    [debuginfo-gdb] debuginfo/nil-enum.rs

[daym]

Fails in Rust 1.25.0.

[daym]

Fails in Rust 1.26.0, 1.27.0 and 1.27.2, too.

[tromey]

$1 = nil_enum::ANilEnum
$2 = nil_enum::AnotherNilEnum

The gdb 8.2 output here is actually more correct. Note though that #54004 is going to change this area, and it provokes a bug in 8.2, which will be fixed in the next gdb release.

[tromey]

This file no longer exists, and GDB 8.2 is rather old, so I am going to close this bug as it is obsolete.