Mixed progress message language

[Mats Behre]

Hi,

I'm using 2.18.2 on a Mac located in Sweden, but my OS language is English.
For some reason Lilypond decides to print some of the progress messages in 
Swedish, like this:

GNU LilyPond 2.18.2
Processing `SopranoSax.ly'
Tolkar...
Tolkar musik...[8][16][24][32][40][48]
F..rbehandlar grafiska objekt...
Finding the ideal number of pages...
Fitting music on 1 page...
Drawing systems...
Layout output to `SopranoSax.ps'...
Converting to `./SopranoSax.pdf'...
Success: compilation successfully completed

I don't remember it doing this, but I can't remember when it changed (in a 
Lilypond or OS change).
Obviously this is a minor annoyance, but if anyone knows an easy way to avoid 
it I'd be grateful.

Thanks
Mats