Re: GPS doesn't work in GNAT GPL

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Ada novice wrote on comp.lang.ada:
>> You loose integration with the gcc, since you will have two
>> versions of gcc installed on the box. That could cause a lot of
>> trouble with maintenance and 3-rd party libraries. 
> 
> GCC now on my machine is picking up the gcc in
> /usr/local/gnat-2012/bin/gcc and 
> 
> $ gcc -v
> Using built-in specs.
> COLLECT_GCC=gcc
> COLLECT_LTO_WRAPPER=/usr/local/gnat-2012/bin/../libexec/gcc/i686-pc-linux-gnu/4.5.4/lto-wrapper
> Target: i686-pc-linux-gnu
[...]
> So what can go wrong having the above?

* A third-party library may build with GNAT GPL but not with GCC or vice
  versa.
* Once you've compiled a library with GNAT GPL you must use GNAT GPL for
  everything that depends on this library.
* You must therefore keep track of which compiler built what library and
  what object file.  Manually.
* When you upgrade your operating system, it is possible that you break
  your installation of GNAT GPL Edition.  This has happened in the past
  with the migration to multilib.
* When you upgrade your operating system, it is possible that you break
  your executables built with GNAT GPL Edition.

> I think the GCC that is already installed on my machines does not
> come with the Ada language enabled.

You think? What about the package gnat?

>> You would also loose some hot bug fixes.
> 
> What kind of fixes? Does AdaCore not periodically fix their GNAT? 

No but I do and I also fix other packages whenever I can.  The other
package maintainers too.

> I had earlier installed pure Debian in a Virtual Box but I got only
> a very small screen with a bad resolution. This problem is very
> common if you make a google search and there is no standard fix to
> it. So yes pure Debian boasts to be the best but it does not seem to
> do much effort as far as hardware compatibility is concerned. If
> people wants to use pure Debian and spend countless hours to tweak
> settings in order to get the proper screen resolution, then it is
> their choice.

I don't know about this problem; I don't run VirtualBox and don't
intend to.
 
> I have Linux mint Debian and Crunchbang Linux in two Virtual Boxes
> and I did not have any problems with screen resolutions. As they are
> both direct derivatives of Debian, so why not use them?

Because, by definition, they will always lag behind Debian and because
there is a possibility that they introduce new bugs; this has happened
in the past in other derivatives.  The Debian maintainers for Ada
expend great effort to ensure that all packages work well together;
derivatives take a snapshot of Debian at an arbitrary time, which may
break this compatibility (this has also happened in the past).

Because the Debian maintainers don't monitor the bug tracking systems
of derivatives.

Because derivatives don't have dedicated Ada maintainers, so if you
ever report a bug to a derivative, chances are nobody will ever look
at it.

> I have earlier installed Debian Ada on Linux mint and on Crunchbang
> and then I got the same error message when launching GPS.

I have no idea what error message you are talking about; please be
precise.

> I do not have the error message with me but the tips popup is not
> displayed when GPS is launched and a message is displayed in the
> message panel in GPS.

Again be precise; vague problem reports are useless.

> Perhaps this is the reason that I went for GPL GNAT and here GPS
> launches well (I had to install the libjpeg62 library though on
> Crunchbang).

GNAT GPL Edition is great if you agree to recompiling most everything
from scratch with every installation.  You'll know what I mean when
you try GtkAda or AWS, when you want to run your executable built
with GNAT GPL Edition on another machine and when you upgrade your
GNAT GPL Edition to a newer version.

Debian brings automatic dependency management, automatic upgrades and
a way to deploy binary executables without requiring end users to
compile anything.  Among other things.

-- 
Ludovic Brenta.
The human resources focus on our projections across the board, while
the gatekeeper prioritizes problem-solving efficiencies.