@node Getting Support and Reporting Bugs
@comment  node-name,  next,  previous,  up
@chapter Getting Support and Reporting Bugs

@menu
* Volunteer Support::
* Commercial Support::
* Reporting Bugs::
@end menu

@node Volunteer Support
@comment  node-name,  next,  previous,  up
@section Volunteer Support

Your primary source of SBCL support should probably be the mailing
list @strong{sbcl-help}: in addition to other users SBCL developers
monitor this list and are available for advice. As an anti-spam
measure subscription is required for posting:

@urlline{https://lists.sourceforge.net/lists/listinfo/sbcl-help}

Remember that the people answering your question are volunteers, so
you stand a much better chance of getting a good answer if you ask a
good question.

Before sending mail, check the list archives at either

@urlline{http://sourceforge.net/mailarchive/forum.php?forum_name=sbcl-help}

or

@urlline{http://news.gmane.org/gmane.lisp.steel-bank.general}

to see if your question has been answered already. Checking the bug
database is also worth it @xref{Reporting Bugs}, to see if the issue
is already known.

For general advice on asking good questions, see

@urlline{http://www.catb.org/~esr/faqs/smart-questions.html}.

@node Commercial Support
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@section Commercial Support

There is no formal organization developing SBCL, but if you need a
paid support arrangement or custom SBCL development, we maintain the
list of companies and consultants below. Use it to identify service
providers with appropriate skills and interests, and contact them
directly.

The SBCL project cannot verify the accuracy of the information or the
competence of the people listed, and they have provided their own
blurbs below: you must make your own judgement of suitability from the
available information - refer to the links they provide, the CREDITS
file, mailing list archives, CVS commit messages, and so on. Please
feel free to ask for advice on the sbcl-help list.

(At present, no companies or consultants wish to advertise paid support
or custom SBCL development in this manual).

@node Reporting Bugs
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@section Reporting Bugs

SBCL uses Launchpad to track bugs. The bug database is available at

@urlline{https://bugs.launchpad.net/sbcl}

Reporting bugs there requires registering at Launchpad. However, bugs
can also be reported on the mailing list @strong{sbcl-bugs}, which is
moderated but does @emph{not} require subscribing.

Simply send email to @email{sbcl-bugs@@lists.sourceforge.net} and the
bug will be checked and added to Launchpad by SBCL maintainers.

@subsection How to Report Bugs Effectively

Please include enough information in a bug report that someone reading
it can reproduce the problem, i.e. don't write

@example
Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
PRINT-OBJECT doesn't seem to work with *PRINT-LENGTH*. Is this a bug?
@end example

but instead

@example
Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
In sbcl-1.2.3 running under OpenBSD 4.5 on my Alpha box, when
I compile and load the file
   (DEFSTRUCT (FOO (:PRINT-OBJECT (LAMBDA (X Y)
                                    (LET ((*PRINT-LENGTH* 4))
                                      (PRINT X Y)))))
     X Y)
then at the command line type
   (MAKE-FOO)
the program loops endlessly instead of printing the object.
@end example

A more in-depth discussion on reporting bugs effectively can be found
at

@urlline{http://www.chiark.greenend.org.uk/~sgtatham/bugs.html}.

@subsection Signal Related Bugs

If you run into a signal related bug, you are getting fatal errors
such as @code{signal N is [un]blocked} or just hangs, and you want to
send a useful bug report then:

@enumerate

@item
@cindex ldb
Compile SBCL with ldb enabled (feature @code{:sb-ldb}, see
@file{base-target-features.lisp-expr}).

@item
Isolate a smallish test case, run it.

@item
If it just hangs kill it with sigabrt: @code{kill -ABRT <pidof sbcl>}.

@item
Print the backtrace from ldb by typing @code{ba}.

@item
Attach gdb: @code{gdb -p <pidof sbcl>} and get backtraces for all threads:
@code{thread apply all ba}.

@item
If multiple threads are in play then still in gdb, try to get Lisp
backtrace for all threads: @code{thread apply all call
backtrace_from_fp($ebp, 100, 0)}. Substitute @code{$ebp} with @code{$rbp}
on x86-64. The backtraces will appear in the stdout of the SBCL
process.

@item
Send a report with the backtraces and the output (both stdout and
stderr) produced by SBCL.

@item
Don't forget to include OS and SBCL version.

@item
If available, include information on outcome of the same test with
other versions of SBCL, OS, ...
@end enumerate
