openSuse 13.2
I have gmp-6.1.1 installed in /usr/local.
pari-2.7.6 finds this but pari-2.8.0.alpha returns the system gmp version 5.1.3

swr@Suse:~> cd PARIGP/pari-2.8.0.alpha/
swr@Suse:~/PARIGP/pari-2.8.0.alpha> ./Configure --with-gmp=/usr/local
Configuring pari-2.8.0 (DEVELOPMENT VERSION)
Checking echo to see how to suppress newlines...
...using -n.
Looking for some tools first ...
...gzip is /usr/bin/gzip
...cc is /usr/bin/cc
...gcc is /usr/bin/gcc
...ld is /usr/bin/ld
...perl is /usr/bin/perl
...zcat is /usr/bin/zcat
Choosing C compiler ...
GNU compatible compiler: gcc version 4.8.3 20140627 [gcc-4_8-branch revision 212064] (SUSE Linux)
Using mt engine single
Given the previous choices, sizeof(long) is 8 chars.
The internal word representation of a double is not needed (64bit).
==========================================================================
Building for: amd64 running linux (x86-64/GMP kernel) 64-bit version
==========================================================================
C compiler is          /usr/bin/gcc -O3 -Wall -fno-strict-aliasing -fomit-frame-pointer    -fPIC
Executable linker is   /usr/bin/gcc  -O3 -Wall -fno-strict-aliasing -fomit-frame-pointer    -Wl,--export-dynamic
Dynamic Lib linker is  /usr/bin/gcc  -shared  $(CFLAGS) $(DLCFLAGS) -Wl,-shared,-soname=$(LIBPARI_SONAME)
Looking in C lib for some symbols...
...Found exp2.
...Found log2.
...Found strftime.
...Found getrusage.
...Found gettimeofday.
...Found sigaction.
...Found TIOCGWINSZ.
...Found getrlimit.
...Found stat.
...Found vsnprintf.
...Found mmap.
...Found waitpid.
...Found setsid.
...Found getenv.
...Found isatty.
...Found alarm.
...Found system.
...I did not find dlopen.
Try again, with -ldl this time...
...Found dlopen.
Checking for optional libraries and headers...
...Found gmp header in /usr/local/include
Using GNU MP, version 5.1.3
...Found X11 header files in /usr/include/X11
...X11 libraries: -lX11
Hi-Res Graphics: X11
Using GNU readline, version 6.2
Installation prefix ? [/usr/local]
...for architecture-independent files (share-prefix) ? [/usr/local/share]
Installation directories for:
...executables (gp, gphelp) ? [/usr/local/bin]
...libraries (libpari) ? [/usr/local/lib]
...include files ? [/usr/local/include]
...manual pages ? [/usr/local/share/man/man1]
...other system-dependent data ? [/usr/local/lib/pari]
...other system-independent data ? [/usr/local/share/pari]
Default is dynamic executable and shared library
==========================================================================
Extracting examples/Makefile.linux-x86_64
Extracting Olinux-x86_64/Makefile
Extracting Olinux-x86_64/paricfg.h
Extracting Makefile
Extracting scripts and macros
...in doc
...in misc
==========================================================================