[SOLVED] Code:Blocks cannot detect gfortran although installed

Issue

I believe my question is similar to this post: Linux: cannot find lgfortran though gfortran is installed. However, since the suggested answer does not fix my problem, there seems no other choice other than asking it again, for a desperate Linux new comer like me.

Here is the problem. I installed GNU fortran compiler 4.8.4 and can find it in terminal

$ which gfortran-4.8 
/usr/bin/gfortran-4.8

and

$ locate gfortran
/usr/bin/gfortran-4.7
/usr/bin/gfortran-4.8
/usr/bin/x86_64-linux-gnu-gfortran-4.7 
/usr/bin/x86_64-linux-gnu-gfortran-4.8
/usr/lib/gcc/x86_64-linux-gnu/4.7/libgfortran.a
/usr/lib/gcc/x86_64-linux-gnu/4.7/libgfortran.so
/usr/lib/gcc/x86_64-linux-gnu/4.7/libgfortran.spec
/usr/lib/gcc/x86_64-linux-gnu/4.7/libgfortranbegin.a
/usr/lib/gcc/x86_64-linux-gnu/4.8/libgfortran.a
/usr/lib/gcc/x86_64-linux-gnu/4.8/libgfortran.so
/usr/lib/gcc/x86_64-linux-gnu/4.8/libgfortran.spec
/usr/lib/gcc/x86_64-linux-gnu/4.8/libgfortranbegin.a
/usr/lib/x86_64-linux-gnu/libgfortran.so.3
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0
/usr/share/doc/gfortran-4.7
/usr/share/doc/gfortran-4.8
/usr/share/doc/libgfortran-4.7-dev
/usr/share/doc/libgfortran-4.8-dev
/usr/share/doc/libgfortran3
/usr/share/man/man1/gfortran-4.7.1.gz
/usr/share/man/man1/gfortran-4.8.1.gz
/usr/share/man/man1/x86_64-linux-gnu-gfortran-4.7.1.gz
/usr/share/man/man1/x86_64-linux-gnu-gfortran-4.8.1.gz
/var/cache/apt/archives/gfortran-4.7_4.7.3-12ubuntu1_amd64.deb
/var/cache/apt/archives/gfortran-4.8_4.8.4-2ubuntu1~14.04_amd64.deb
/var/cache/apt/archives/libgfortran-4.7-dev_4.7.3-12ubuntu1_amd64.deb
/var/cache/apt/archives/libgfortran-4.8-dev_4.8.4-2ubuntu1~14.04_amd64.deb
/var/cache/apt/archives/libgfortran3_4.8.4-2ubuntu1~14.04_amd64.deb
/var/lib/dpkg/info/gfortran-4.7.list
/var/lib/dpkg/info/gfortran-4.7.md5sums
/var/lib/dpkg/info/gfortran-4.8.list
/var/lib/dpkg/info/gfortran-4.8.md5sums
/var/lib/dpkg/info/libgfortran-4.7-dev:amd64.list
/var/lib/dpkg/info/libgfortran-4.7-dev:amd64.md5sums
/var/lib/dpkg/info/libgfortran-4.8-dev:amd64.list
/var/lib/dpkg/info/libgfortran-4.8-dev:amd64.md5sums
/var/lib/dpkg/info/libgfortran3:amd64.list
/var/lib/dpkg/info/libgfortran3:amd64.md5sums
/var/lib/dpkg/info/libgfortran3:amd64.postinst
/var/lib/dpkg/info/libgfortran3:amd64.postrm
/var/lib/dpkg/info/libgfortran3:amd64.shlibs
/var/lib/dpkg/info/libgfortran3:amd64.symbols

So gfortran seems installed, although I don't understand why 4.7 version is still there after my removing it.

In setting Global Compiler Settings of Code:Blocks, when I choose GNU Fortran Compiler, and its Toolchain Executables, I tried the installation directory as

/usr 

/usr/bin 

and

/usr/lib/gcc/x86_64-linux-gnu/4.8/

as suggested in the previous post, Code:Blocks tell me

could not auto-detect installation path of "GNU Fortran Compiler".....

More details of compiler configuration is here in the image (Thanks to Mike's suggestion).

And here's the full list of compilers on my computer:

List of Compliers

Solution

Your posting shows that you have both gfortran-4.7 and gfortran-4.8 installed under /usr/bin.

Having multiple GCC Fortran compilers (or multiple C or C++ compilers) is perfectly valid and commonplace. Code::Blocks will allow you configure as many Fortran compilers as you have got, provided you give them different names. It's also fine if you just want to configure one of them as the "GNU Fortran Compiler" and ignore the others.

But in any case, Code::Blocks must be able to unambiguously identify the installed compiler that you are calling "GNU Fortran Compiler". You have specified the Compiler's installation directory as /usr/bin and have left the Program files compiler name as gfortran.

There is no such compiler as /usr/bin/gfortran in your system, and there is no program called gfortran anywhere in your PATH. You have /usr/bin/gfortran-4.7 and /usr/bin/gfortran-4.8. As you have installed both of them, Code::Blocks assumes you want both of them. It can't tell which one of them you want to configure as "GNU Fortran Compiler".

So:-

• Set Compiler's installation directory = /usr/bin
• In Program files, change all occurrences of gfortran to gfortran-4.8, if you want "GNU Fortran Compiler" to mean gfortran-4.8.
• OK out.

Answered By - Mike Kinghan

Answer Checked By - Gilberto Lyons (WPSolving Admin)