Re: [Plplot-general] Problem building on Linux

[Alan W. I. <Ala...@gm...>]

On 2018-09-11 20:07+0100 Phil Rosenberg wrote:

> Hi Alan
> I just wanted to let you know that your recent commit seems to have fixed all
> the strange output I was getting at the end of my cmake command.

Hi Phil:

I was very happy to receive that encouraging news concerning all the build-system
improvements I have been doing.

>
> I am still getting a build arror though
> Generating test_dyndrivers_dir/wxwidgets.driver_info
> Could not open driver module
> /home/users/prosenberg01/junest/src/plplot-plplot/build/drivers/wxwidgets
> libltdl error: file not found
>
>
> This comes down to the execution of an execuatable
> <build_dir>/drivers/test-drv-info. It is run as follows
> ./test-drv-info "" wxwidgets
> and it retuns an error, saying could not open driver module
> <build_dir>/drivers/wxwidgets
>
> I've found that test-drv-info is an executable built by plplot. It
> uses the function lt_dlopenext to open the drivers and then extract
> some symbols. From what I can tell from the source the lt_dlopenext
> function returns null indicating the file did not exist or could not
> be opened. The relevant file (wxwidgets.so) is definitely there, so I
> guess there must be some reason why it cannot be opened.
>
> I'm at a complete loss now as this is beyond my linux knowledge - any
> suggestions?

The test-drv-info application was implemented long ago to test at
build time whether our dynamic devices would load properly.  But
sometimes on Windows (but never on Linux) test-drv-info would say the
device could not be loaded properly, but the equivalent code to
dynamically load a device in the PLplot core library would work fine!
But our Windows developers could never figure out that discrepancy
between the two results.

Anyhow, you *might* have run into this case yet again.  So to check
that specify -DTEST_DYNDRIVERS=OFF (which will drop the build-time
test).  That should let you build everything without problems, but, of
course, you should test that result at run-time to make sure the
equivalent code in the core library works, i.e., by specifying -dev
wxwidgets for some run-time test.

If that turns out to be the case, (i.e.,test-drv-info application does
not work while equivalent core code does work), that is a useful
workaround for you, but it would also be great in this case if you
could figure out the fix required to make sure test-drv-info works
*exactly* like the core code on your Windows platform so you don't
have to use the workaround.

Alan
__________________________
Alan W. Irwin

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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Linux-powered Science
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