undefined reference to `_D5xxxx6yyyyy12__ModuleInfoZ'

[bioinfornatics via Digitalmars-d-learn]

Dear,

maybe I'm too tired to see my errors or they are a bug. See below
I have this:
.
|-- fasta.d
`-- src
     `-- nicea
         |-- metadata.d
         |-- parser.d
         `-- range.d

when I try to build it:

$ dmd -I./src/  ./fasta.d 2>&1
fasta.o:(.rodata+0x1f8): undefined reference to
`_D5nicea6parser12__ModuleInfoZ'
collect2: error: ld returned 1 exit status
--- errorlevel 1

If I merge all files in one that build!

What is it ?

I tried to minimize the problem with dustmite but it give to me 
at end an empty file …

thanks