Gcc 4.9.4 cannot find Isl 0.12.2 (or 0.14)

[Marc Glisse]

On Tue, 27 Oct 2020, Maria Clara via Gcc-help wrote:

> Hello. I am trying to configure gcc with:
>
> ./configure --prefix=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/GCC-4.94/
> --with-gmp=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Gmp-4.3.2/
> --with-mpfr=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Mpfr-2.4.2/
> --with-mpc=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Mpc-0.8.1/
> --with-cloog=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Cloog-0.18.1/
> --with-isl=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Isl-0.12.2/
>
> and all I receive it is:
>
> checking for version 0.10 of ISL... no
> checking for version 0.11 of ISL... no
> checking for version 0.12 of ISL... no
> checking for version 0.14 of ISL... no
> checking for version 0.15 of ISL... no
> configure: error: Unable to find a usable ISL.  See config.log for details.
>
> Then I proceeded to look in config.log. There I saw things like:
>
> configure:5894: checking for version 0.10 of ISL
> configure:5913: gcc -o conftest -g -O2
> -I/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Isl-0.12.2//include
> -I/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Gmp-4.3.2//include
> -I/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Mpfr-2.4.2//include
> -I/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Mpc-0.8.1//include
>   -L/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/Isl-0.12.2//lib
> conftest.c  -lisl >&5
> configure:5913: $? = 0
> configure:5913: ./conftest
> ./conftest: error while loading shared libraries: libisl.so.10: cannot
> open shared object file: No such file or directory
[...]

See the first 2 questions of https://gcc.gnu.org/wiki/FAQ . Gcc does not 
set a runpath, so you need to add one yourself (LD_LIBRARY_PATH, or 
-Wl,-rpath,... I don't know where, possibly LDFLAGS, *_LDFLAGS, 
LD_RUN_PATH, etc) or make sure one is not needed (install the shared 
libraries in a standard location or use static libraries, as happens with 
contrib/download_prerequisites).

-- 
Marc Glisse