[kingeorge]

Dear All,


I would greatly appreciate if someone could help around with this issue which has never appeared before.

Here is the problem:

/home/vladj/OpenFOAM/OpenFOAM-5.x/platforms/linux64GccDPInt32Opt/src/surfMesh/surfaceFormats/stl/STLsurfaceFormatASCII.L.C:302:10: fatal error: FlexLexer.h: No such file or directory
 #include <FlexLexer.h>
          ^~~~~~~~~~~~~
compilation terminated.

Thank you very much in advance!

[pbrady2013]

Hi Vladimir,


I think that its looking for a specific development component in the GNU flex library:


https://www.gnu.org/software/flex/


As for a new error is there something different in this install? Base OS, version of OF, changes in compiler search paths?


I'm good at fiddling with my bash paths as I have multiple versions of OF installed at the same time. Sometimes there is confusion but usually they are isolated and plat nice.



Cheers,
-pete

[kingeorge]

Hello Pete,
I appreciate you're trying to help.


Well, there is nothing unusual in the installation procedure for this version of OF which is 5.x. I did compile it without any problem on the Linux Mint version which was based on Ubuntu 16.04. However, now I switched to the latest Linux Mint (based on Ubuntu 18.04) and it aborts compilation.


I have always followed this procedure:


http://openfoamwiki.net/index.php/In...u#Ubuntu_18.04


and never had any problem until now.


This is all I can say for the moment.


Cheers and thanks again,
Vladimir

[pbrady2013]

Hi,


I spend more time in RedHat land and have not used Mint myself but I'll see if I can give it a try when I get into the office tomorrow.



Skimming that instruction set though I note that in RHEL I sometimes have to explicitly install both the base and *-devel packages to get the header files. Maybe Tara update changed that?


Cheers,
-pete

[pbrady2013]

Hi,


Sorry for the delay in responding. I've not had time to spin up a Mint or Ubuntu to check.


As far as I can tell the libfl-dev package is required to install this header. This package is not explicitly installed via the instruction set you linked to and it may have been installed through dependencies in the past.


Can you check that this package is installed?


Assuming it is then its back to checking the search paths.


It looks like some packages have been rearranged as there is a "flex-old" package that contains the header you are missing. That package would have been installed under the old instructions.



Hope that helps,
-pete

[kingeorge]

Hello Pete!


As you suggested:


sudo apt-get install libfl-dev

and compilation went through the critical stage. So far so good.


Thank you very much. I am back in business.


Cheers,
V

[pbrady2013]

Great news. Have fun Foaming!


Cheers,
-pete

[wyldckat]

Greetings to all!

I was really intrigued what happened with the difficulties on Linux Mint, just because of one single package... and I've finally managed to figure out that it has to do with how Linux Mint has disabled the installation of recommended packages when using apt.

By using this command:

grep "APT::Install-Recommends" /etc/apt/apt.conf.d/*

• On Linux Mint we get:
  

  /etc/apt/apt.conf.d/00recommends:APT::Install-Recommends "false";

• On Ubuntu 18.04 we don't get anything.
• On Ubuntu 16.04 we get:
  

  /etc/apt/apt.conf.d/99synaptic:APT::Install-Recommends "true";

What this means is that on Ubuntu using the package name "flex" is enough to also installing the packages "libfl-dev" and "libfl2", but on Linux Mint we should use "libfl-dev" instead, given that this package has a hard-dependency on the other two, instead of just a recommendation.


Therefore, I've updated the instructions at openfoamwiki.net for 5.x, 6 and dev to install this package instead of just "flex".


What I find strange is that this problem should have started since 2014, given that this kind of issue was already discussed back then here: https://forums.linuxmint.com/viewtopic.php?t=185770 - and I don't remember ever seeing this issue being reported in the past here on the OpenFOAM forum(s)...


Best regards,
Bruno