What causes the debugger to consistently pull the plug?
lazarus / 12-Debugger

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dkjMusic · 2011-09-29 23:41

...on this one project.

I checked for memory leaks via heaptrc and found none, thinking that
might be the (irrational) reason.

The dialog gives:

The GDB command:
"-file-exec-and-symbols "
did not return any result

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Martin_fr · 2011-09-30 09:21

Strange. this looks like the filename of the executable is missing.(It
is supposed to stand behind -file-exec-and-symbols).
And also instead of a normal error it seems your gdb does crash.

Can you please provide the following info (there may be more required,
but somewhere to start):

- The revision of Lazarus:
 Go to menu "view" => "IDE Internals" => "About IDE"
 Please copy the entire information from the dialog. (You can leave
out the "Environment variables" if you consider them containing
private info)

- The exact version of your GDB.exe.
  This may be included in the next item "debug output" => you may
whish to check that first
 Lazarus now comes with 7.3-2, but i don't know about code-typhon.
From Environment options dialog, find the location of your gdb.exe.
Open a command prompt "cmd.exe" and execute the gdb.exe

- The output of the "Debug output window, as described on:
http://wiki.lazarus.freepascal.org/GDB_Debugger_Tips#Create_a_new_Repo
rt

- The complete path and filename of your project (the *.lpr file)
Please confirm, that the project is either an application, or a
program. But not a library or other type.

- Please "build" your project.
  Menu "Run" => "Build" (this is the 2nd entry in the menu)
And copy the content of the "message" window, using "copy all shown
and hidden messages to clipboard" from the context menu (right mouse)

Please locate the generated exe, and confirm it's path and name.

- Please check from the menu "Run" => "Run parameters", that all
fields are empty. No host or launching app

- Please confirm if you changed/added any path in the "project
options" ("project" menu)


Sorry, lot's of question, but it's the needle in the haystack. Need to
find why your executable filename is not given to the debugger.

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dkjMusic · 2011-10-01 08:28

Martin, your requested info is attached.

Thanks so much for your help on this.

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Martin_fr · 2011-10-01 09:04

Did you get the same error?
QuoteThe GDB command:
"-file-exec-and-symbols "
did not return any result
Because the "debug output" tells an entirely different story.

The filename was present, and the exe loaded (which the above error
would indicate *not* to have happened).

the error this time is:
Quote&"../../gdb-7.2/gdb/printcmd.c:1916: internal-error:
clear_dangling_display_expressions: Assertion `objfile->pspace ==
solib->pspace' failed.\nA problem internal to GDB has been
detected,\nfurther debugging may prove unreliable."
However it may display something about "exec-continue" (not sure).

In any case similar errors had been observed
(http://bugs.freepascal.org/view.php?id=19883) and in some cases been
fixed using gdb 7.3-2
Download at
http://svn.freepascal.org/svn/lazarus/binaries/i386-win32/gdb/bin
Libraries go into the same directory as gdb.exe. All files originally
from mingw.


If gdb 7.3-2 does not fix it, then look at the debug-output again, but
with 7.3-2.
If it still reports an "internal error" of gdb , then the problem is a
bug in gdb.

It may be caused by one of your installed software (one of the
libraries that get loaded); even maybe a printer driver....
Uninstalling them might not be an option.
Yet if it is a bug in gdb, it can't be fixed in Lazarus neither.

Also if gdb 7.3-2 does not work, there is a very, very, very slim
change that 6.8.3 or 6.7.5 do work. Both can be downloaded from mingw
(gdb.exe only). But it is really not very likely....

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dkjMusic · 2011-10-01 23:43

Martin, I updated my Lazarus/FPC/GDB install via CodeTyphon 2.20 which
has GDB v. 7.3.

My project now executes perfectly in the IDE with the debugger
stopping on its own when it should.

Thanks again for your priceless help.