Oracle 12 client fails to compile Sources on Solaris 10 x86 with a dump

After installing the Oracle 12 client on a Solaris 10 x86 box and starting the compilation with
proc, proc immediately dumps a core during parse:

Pro*C/C++: Release 12.1.0.2.0 - Production on Wed Nov 4 10:25:09 2015

Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.

System default option values taken from: /export/home/oracle/product/12.1.0/client_2/precomp/admin/pcscfg.cfg

dbgc_init_all failed with ORA-48141
ORA-00600: internal error code, arguments: [17998], [2], [], [], [], [], [], [], [], [], [], []
ORA-00600: internal error code, arguments: [17998], [2], [], [], [], [], [], [], [], [], [], []


----- Call Stack Trace -----
calling              call     entry                argument values in hex      
location             type     point                (? means dubious value)     
-------------------- -------- -------------------- ----------------------------
skgudmp()+106        call     FC7AB9C4             8042FB0 1 60 FCC277AC
kgeasi()+309         call     skgudmp()            87283C8 3 1 FD815EFE
pcgini()+680         call     kgeasi()             87283C8 8755D70 464E 2 1 0 2
                                                   0
pc2main()+1690       call     pcgini()             8044380 8044880 80444A0
                                                   80445D0 8043520 865FD20 0
                                                   80445F0
pcmain()+42          call     pc2main()            870DB48 0 0 A 870DE48
                                                   FEFC2BF4 FEF90690 80959EC
lpmcall()+977        call     pcmain()             870DB48 0 0 A 870DE48 86EA298
                                                   86E65E8 8045AA0
lpmpmai()+369        call     FC2284CC             8045B10 804612C 0 A 8045DC0
main()+296           call     lpmpmai()            8045B8C 8045BB0 A 8045D98
_start()+103         call     main()               A 8045D98 8045DC4 8045D8C

Call stack signature: 0xbae219e83bd8097a



call stack performance statistics:
total                  : 0.006000 sec
setup                  : 0.000000 sec
stack unwind           : 0.000000 sec
symbol translation     : 0.004000 sec
printing the call stack: 0.001000 sec
printing frame data    : 0.000000 sec
printing argument data : 0.000000 sec


After installing the before mentioned missing package SUNWeu8os the problem still occurred.

On a community-Page I got the hint for the problem:

There is a problem in using the diag-Directory:
First setting the access-mode to 777 on the diag  and after the first compile run setting it to
775 and the proc-Compiler from the Oracle 12 Client works again.