invalid or corrupt file: duplicate COMDAT / Previous Definition Different

[Anonymouse]

I haven't been testing my project on Windows for a while, and on 
top of having issues with out of memory errors when unittesting I 
see I can't build it normally either. dmd is 2.078.0.

$ dub build -c cygwin -a x86_64
Performing "debug" build using dmd for x86_64.
kameloso 1.0.0-beta.2+commit.57.g90fdd1d: building configuration 
"cygwin"...
Linking...
kameloso.obj : fatal error LNK1179: invalid or corrupt file: 
duplicate COMDAT 
'_D8kameloso7plugins6common8BotRegex6__ctorMFNcxEQBuQBoQBj10NickPolicyS3std5regex8internal2ir__T5RegexTaZQjZSQEcQDwQDrQDn'
Error: linker exited with status 1179
dmd failed with exit code 1179.

$ dub build -c cygwin
Performing "debug" build using dmd for x86.
kameloso 1.0.0-beta.2+commit.57.g90fdd1d: building configuration 
"cygwin"...
Linking...
OPTLINK (R) for Win32  Release 8.00.17
Copyright (C) Digital Mars 1989-2013  All rights reserved.
http://www.digitalmars.com/ctg/optlink.html
.dub\build\cygwin-debug-windows-x86-dmd_2078-270D5D6B34387418CFDA6A068E7A60D9\kameloso.obj(kameloso)  Offset 7A92EH Record Type 00C3
  Error 1: Previous Definition Different : 
_D8kameloso7plugins6common8BotRegex6__ctorMFNcxEQBuQBoQBj10NickPolicyS3std5regex8internal2ir__T5RegexTaZQjZSQEcQDwQDrQDn
.dub\build\cygwin-debug-windows-x86-dmd_2078-270D5D6B34387418CFDA6A068E7A60D9\kameloso.obj(kameloso)  Offset 7AE18H Record Type 00C3
  Error 1: Previous Definition Different : 
_D8kameloso7plugins6common8BotRegex6__ctorMFNcS3std5regex8internal2ir__T5RegexTaZQjZSQDfQCzQCuQCq
Error: linker exited with status 2
dmd failed with exit code 2.

LDC 1.7.0 builds just fine.

There are similar error messages when compiling on linux, but 
they don't error out (linking succeeds despite them).

/usr/bin/ld: Warning: size of symbol 
`_D8kameloso7plugins6common8BotRegex6__ctorMFNcxEQBuQBoQBj10NickPolicyS3std5regex8internal2ir__T5RegexTaZQjZSQEcQDwQDrQDn' changed from 46 in .dub/build/posix-debug-linux.posix-x86_64-dmd_2078-8E23DC2771FEB27EF0FE1CC8F3984CAA/kameloso.o to 49 in .dub/build/posix-debug-linux.posix-x86_64-dmd_2078-8E23DC2771FEB27EF0FE1CC8F3984CAA/kameloso.o
/usr/bin/ld: Warning: size of symbol 
`_D8kameloso7plugins6common8BotRegex6__ctorMFNcS3std5regex8internal2ir__T5RegexTaZQjZSQDfQCzQCuQCq' changed from 40 in .dub/build/posix-debug-linux.posix-x86_64-dmd_2078-8E23DC2771FEB27EF0FE1CC8F3984CAA/kameloso.o to 43 in .dub/build/posix-debug-linux.posix-x86_64-dmd_2078-8E23DC2771FEB27EF0FE1CC8F3984CAA/kameloso.o

I don't have a reduced testcase yet. I figured I'd ask if it's 
something known before making the effort.