[Pw_forum] ifc and linux

[Jonathan Breeze]

Dear PWscf users,

I thought I would post a message to you all about my recent experiences 
with Intel Fortran Compiler and Linux.
I noticed a while back that Michal Lemieszewski had a problem with 
compiling PWscf to run on a Linux PC.   I had managed to compile PWscf 
on a machine running Linux Redhat 8.1 but when I tried to compile on 
Redhat 9.0, the same errors that Michal reported where found:

/opt/intel/compiler70/ia32/lib/libIEPCF90.a(f90file.o)(.text+0x4746): In
function `FileOpen':
:/ undefined reference to `errno'
//opt/intel/compiler70/ia32/lib/libIEPCF90.a(f90fioerr.o)(.text+0x4d3): In
function `f_f77ioerr':
:/ undefined reference to `__ctype_b'
//opt/intel/compiler70/ia32/lib/libIEPCF90.a(f90fioerr.o)(.text+0x6d9): In
function `f_fiomess.':
:/ undefined reference to `errno'
//opt/intel/compiler70/ia32/lib/libIEPCF90.a(f90fioerr.o)(.text+0x76b): In
function `f_seterrno':
:/ undefined reference to `errno'
/make[1]: *** [all] Error 1
make: *** [pw] Error 2

This is due to an incompatability between Intel Fortran Compiler 7.0 and 
7.1 with new versions of the GNU libc library.  Current versions of ifc 
are compatible with glibc 2.2.3, 2.2.93 and 2.2.4.  Unfortunately, 
Redhat 9.0 and other recent releases of Linux use glibc 2.3.1 or 2.3.2.

The only way I found around this problem was to either to only use 
Redhat 8.1 or earlier releases or link in a libc-2.2.93.so library 
during the build process.
Once the libc-2.2.93 library is linked in,  everything compiles happily. 
I use the option -L/$(PWDIR)/ -lc-2.2.93 added to the LDFLAGS line, 
after placing a copy of the library in the PWscf directory.  This 
solution is not very elegant, but works.  

I was wondering if anyone else has had similar troubles, and if so, have 
you found a more elegant - less nasty - solution ?

Kind regards,

Jonathan

P.S> Dear Paolo,  thankyou for the help with D3.  I am getting good 
results!!