linkererrors when reducion phobos with dustmite

[berni44]

As mentioned on the dustmite website [1] I copied the folder std 
from Phobos in a separate folder and renamed it to mystd. The I 
changed all occurences of std by mystd in all files.

That works most of the time, but sometimes I get hundreds of 
linker errors I do not understand:

$> dmd -main -unittest -g -run mystd/variant.d

/usr/bin/ld: variant.o:(.data.rel.ro+0x68): undefined reference 
to `_D5mystd4meta12__ModuleInfoZ'
/usr/bin/ld: variant.o:(.data.rel.ro+0x70): undefined reference 
to `_D5mystd6traits12__ModuleInfoZ'
/usr/bin/ld: variant.o:(.data.rel.ro+0x78): undefined reference 
to `_D5mystd8typecons12__ModuleInfoZ'
...

Does anyone know, what's the problem here and how to get arround 
this?

[1] 
https://github.com/CyberShadow/DustMite/wiki#minimizing-the-standard-library