Hard link problem during build

Hello

I am working with a filesystem mounted via nfs.
this system is
http://www.active-circle.com/contenu-29-gb.htm

It seems that it do not allow hard linkage. Nevertheless soft linkage is allow.

So the build process failed during the link of built-in commands.
git-merge-subtree$X: target and
$(BUILT_INS): target.

Is it necessary to do hard link instead of soft link ?

Thanks

Frédéric