Hi,
they are regularily bred in Germany.
G. petricolus -as the name implies- is a sandstone dweller which spends a lot of its time underneath rockspurs. Thus the viv should have a fake rock backwall with many crevices and spurs. Uncommon for a Gekko species, males and females differ a lot in coliouration. While males have quite resemblance of
G. ulikovskii, females do look very similar to
G. grossmanni.
Other than tokays, they do not protect eggs and eat their young.
Peter Harbig is one of the most experienced keepers of this species and he also visited their natural habitat several times and spend a lot of time watching these geckos in the wild.
I would suggest to contact him for more detailed information on husbandry.
Maybe you can start via his profile in the DGHT forum (German Society for herpetology and herpetoculture)
DGHT-Foren
BR
Ingo