Error building gnucash 1.8.12

[Rauch Christian]

I'm trying to build gnucash 1.8.12 as rpm.

it compiles fine, but on starting gnucash, it exits with the error

ERROR: In procedure dynamic link:
ERROR: file: "libgw-gnc", message: "/usr/lib/libgw-gnc.a: invalid ELF 
header"

Gnucash 1.8.11 builds fine on the same system and works!

Both in 1.8.11 and 1.8.12 the option --enable-error-on-warning=no had to 
be added to configure to work.

The file /usr/lib/libgw-gnc.a does not exist on my system with an 
self-built g-wrap 1.3.4
There are the following files:
libgw-gnc.la
libgw-gnc.so
libgw-gnc.so.0
libgw-gnc.so.0.0.0

Anyone knows why this happens?

Regards,
rauch