ocamlrpcgen no longer works on Gutsy. Probably a wrongly stripped binary

[David MENTRÉ]

Hello,

The command line options of ocamlrpcgen (from libocamlnet-ocaml-bin package) no longer work on Gutsy (there were no issues on Feisty).

$ ocamlrpcgen -cpp none -int unboxed -hyper int64 -aux net/messages.xdr
Unknown option -cpp.
$ ocamlrpcgen -int unboxed -hyper int64 -aux net/messages.xdr
Unknown option -int.
$ ocamlrpcgen -hyper int64 -aux net/messages.xdr
Unknown option -hyper.

After a post on <email address hidden> mailing list, it seems that this is due to a wrongly stripped binary. OCaml binaries should *never* been stripped because strip removes the embedded bytecode.
  http://lists.debian.org/debian-ocaml-maint/2008/01/msg00039.html

This is confirmed by following command:
$ ocamlrpcgen net/messages.xdr
Fatal error: the file net/messages.xdr is not a bytecode executable file

Currently libocamlnet-ocaml-bin package is broken on Gutsy (and probably others if other OCaml binaries are stripped).

Yours,
d.

[David MENTRÉ (dmentre)]

A Debian developer (Stefano Zacchiroli) suggested that the unneeded strip was done at package building: http://lists.debian.org/debian-ocaml-maint/2008/01/msg00061.html

Unfortunately, after looking at the .deb patch applied to the original package (http://archive.ubuntu.com/ubuntu/pool/universe/o/ocamlnet/ocamlnet_2.2.7-1.diff.gz), the Ubuntu package seems to have the relevant DEB_STRIP_EXCLUDE lines:
+DEB_STRIP_EXCLUDE += usr/bin/netplex-admin # OCaml custom bytecode binaries can't be striped
+DEB_STRIP_EXCLUDE += usr/bin/ocamlrpcgen

So maybe the stripping is done at another level or the DEB_STRIP_EXCLUDE rule is not taken into account. I don't know.

[Michael Bienia (geser)]

Can you provide a test file so I can check if it's fixed in hardy? (I'm no ocaml programmer).

[David MENTRÉ (dmentre)]

Here is a test file. Use it with following command line:

  ocamlrpcgen -cpp none -int unboxed -hyper int64 -aux messages.xdr

It should produce several messages_*.ml and messages_*.mli files.

[Martin Pitt (pitti)]

Seems that merely adding a .gnu_debuglink ELF section breaks the binaries. Meh :/

We need to fix that in pkg-create-dbgsym. There needs to be a robust way to detect such a binary. Do they have a special section (objdump -x or readelf -h)?

[Martin Pitt (pitti)]

seems that this is a working test:

  objdump -x binary | grep -qw caml_release_bytecode

[Martin Pitt (pitti)]

objdump -t binary is sufficient, too.

[David MENTRÉ (dmentre)]

Hello Martin,

I've asked to OCaml developers. Xavier Leroy, lead OCaml developer, told me that:
 * the "objdump -x binary | grep -qw caml_release_bytecode" or "objdump -t binary" patterns could be used;
 * it would be better also to test an OCaml magic number at the last 12 bytes of the binary. The magic pattern to match is "Caml1999X[0-9][0-9][0-9]". So a

  tail -c 12 | egrep -q "Caml1999X[0-9][0-9][0-9]"

should do the trick.

Yours,
d.

[Martin Pitt (pitti)]

I think I'll fix this completely differently: I'll fix the dh_strip wrapper to pass the set of ignored files (-X file) to pkg_create_dbgsym, and have that one not touch any ignored file.

[David MENTRÉ (dmentre)]

Hello Martin,

2008/1/14, Martin Pitt <email address hidden>:
> I think I'll fix this completely differently: I'll fix the dh_strip
> wrapper to pass the set of ignored files (-X file) to pkg_create_dbgsym,
> and have that one not touch any ignored file.

Should this list of ignored files be manually updated or is it an
automatic process?

Let me know if I can test new packages.

Yours,
d.

[Michael Bienia (geser)]

The package specifies already that usr/bin/netplex-admin and usr/bin/ocamlrpcgen shouldn't be stripped. The problem is that pkg_create_dbgsym didn't have this information and added a link to the debug symbols (although those binaries doesn't get stripped later) and that broke those binaries too.
The fix is now to pass this information to pkg_create_dbgsym so it doesn't try to add that link to the debug symbols for package which are stripped later anyway.
Once pkg_create_dbgsym is fixed, a (no-change) rebuild of ocamlnet is necessary to fix the package too.

[Martin Pitt (pitti)]

Will do a no-change upload once the fixed pkg-create-dbgsym is built and in the archive.

[Launchpad Janitor (janitor)]

This bug was fixed in the package pkg-create-dbgsym - 0.24

---------------
pkg-create-dbgsym (0.24) hardy; urgency=low

  * Add tests/dhtest.nostrip: Ignore crash2 for dh_strip, and add an assertion
    that the file isn't touched by dh_strip. This reproduces LP #180364.
  * Parse dh_strip's -X options in the wrapper and pass them to
    pkg_create_dbgsym. Do not touch any files which match these patterns. This
    avoids adding GNU debuglinks to ELF binaries which must not be touched at
    all, like Ocaml bytecode. (LP: #180364)
  * tests/run: Do not expect a dbgsym package for test .debs with 'nostrip' in
    the name (as used by the tests/dhtest.nostrip test case).

 -- Martin Pitt <email address hidden> Thu, 21 Feb 2008 17:55:07 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package ocamlnet - 2.2.8.1-1build1

---------------
ocamlnet (2.2.8.1-1build1) hardy; urgency=low

  * No-change rebuild against fixed pkg-create-dbgsym. (LP: #180364)

 -- Martin Pitt <email address hidden> Fri, 22 Feb 2008 12:08:34 +0100

[David MENTRÉ (dmentre)]

Hello,

Launchpad Bug Tracker <email address hidden> writes:

> This bug was fixed in the package ocamlnet - 2.2.8.1-1build1

Unfortunatly, the bug is not fixed.

Even with package version 2.2.8.1-1build1, program ocamlrpcgen is still
broken. :-(

(hardy-chroot)david@morgana:~$ dpkg -l *ocamlnet*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-========================-========================-================================================================
ii libocamlnet-ocaml 2.2.8.1-1build1 OCaml application-level Internet libraries - core runtime librar
ii libocamlnet-ocaml-bin 2.2.8.1-1build1 OCaml application-level Internet libraries - binaries
ii libocamlnet-ocaml-dev 2.2.8.1-1build1 OCaml application-level Internet libraries - core development li
un libocamlnet-ocaml-doc <none> (no description available)

(hardy-chroot)david@morgana:~$ ocamlrpcgen
No bytecode file specified.

(hardy-chroot)david@morgana:~$ ocamlrpcgen --help
Unknown option --help.

Here is the expected behavior (in Debian Etch):

(etch-chroot)root@morgana:/# ocamlrpcgen --help
usage: ocamlrpcgen [-aux] [-clnt] [-srv]
                   [-int (abstract | int32 | unboxed) ]
                   [-hyper (abstract | int64 | unboxed) ]
[...]

Sincerely yours,
david
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[Martin Pitt (pitti)]

Not quite fixed yet, pkg-create-dbgsym needs to get along with spaces between -X and the pattern.

[Launchpad Janitor (janitor)]

This bug was fixed in the package pkg-create-dbgsym - 0.25

---------------
pkg-create-dbgsym (0.25) hardy; urgency=low

  * tests/dhtest.nostrip: Add another test case for dh_strip blacklisting with
    a space between -X and the argument. This reproduces the followup problem
    in LP #180364.
  * dh_strip: Fix option parsing to get along with spaces between -X and the
    argument. (LP: #180364)

 -- Martin Pitt <email address hidden> Tue, 26 Feb 2008 16:05:28 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package ocamlnet - 2.2.8.1-1build2

---------------
ocamlnet (2.2.8.1-1build2) hardy; urgency=low

  * No-change rebuild against even more fixed pkg-create-dbgsym. (LP: #180364)

 -- Martin Pitt <email address hidden> Wed, 27 Feb 2008 11:26:35 +0100

[David MENTRÉ (dmentre)]

Hello,

Launchpad Bug Tracker <email address hidden> writes:

> This bug was fixed in the package ocamlnet - 2.2.8.1-1build2

I confirm the bug is fixed in this package. Many thanks Martin!

Yours,
d.
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