[Fedora-packaging] FESCo notes on OCaml guidelines change

[Richard W.M. Jones]

On Thu, Mar 13, 2008 at 07:34:38PM -0500, Jason L Tibbitts III wrote:
> Of course, we should still try to address the issue.  Is there
> actually a demonstrable problem here?  What can go wrong without some
> arch-specific dependencies on the main ocaml package?  Can you have
> just the 32-bit ocaml installed on a 64-bit machine and install a
> 64-bit module without rpm/yum complaining about dependency problems or
> pulling in the 64-bit ocaml package?  (No 64-bit machine I can afford
> to screw with at the moment.)

I think I'm starting to understand the problem here.  Take as an
example the ocaml-curses library.

The Rawhide repository[1] contains three packages related to this
library:

  ocaml-curses-0.1-7.20020319.fc9.x86_64.rpm
  ocaml-curses-devel-0.1-7.20020319.fc9.i386.rpm
  ocaml-curses-devel-0.1-7.20020319.fc9.x86_64.rpm

The ocaml-curses-devel.i386 RPM is completely useless.  The base OCaml
compiler would never even get so far as to look in its install
directory /usr/lib, because it is configured to always look in
/usr/lib64.  There is no concept of the -m32/-m64 switch as in gcc.
It will always build only a single type of binary.

The way the dependencies are set up, the user could request
ocaml-curses-devel.i386 (they'd have to request it explicitly on
x86-64, presumably implicitly on ppc64??) and yum would install
ocaml-curses-devel.i386, ocaml-curses.x86_64 and ocaml.x86_64 [2].
This would not give them a working curses development environment.
For that they'd need ocaml-curses-devel.x86_64.

I don't understand how to exclude or remove those i386 packages from
being built and placed in the repository, but if you give me some clue
I can update the guidelines appropriately.

Rich.

[1] http://download.fedora.redhat.com/pub/fedora/linux/development/x86_64/os/Packages/

[2] Tested on a Rawhide machine:

# yum install ocaml-curses-devel.i386

development               100% |=========================| 2.4 kB    00:00     
Setting up Install Process
Parsing package install arguments
Resolving Dependencies
--> Running transaction check
---> Package ocaml-curses-devel.i386 0:0.1-7.20020319.fc9 set to be updated
--> Processing Dependency: ocaml-curses = 0.1-7.20020319.fc9 for package: ocaml-curses-devel
--> Running transaction check
---> Package ocaml-curses.x86_64 0:0.1-7.20020319.fc9 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size 
=============================================================================
Installing:
 ocaml-curses-devel      i386       0.1-7.20020319.fc9  development        39 k
Installing for dependencies:
 ocaml-curses            x86_64     0.1-7.20020319.fc9  development        56 k

Transaction Summary
=============================================================================
Install      2 Package(s)         
Update       0 Package(s)         
Remove       0 Package(s)         

Total download size: 95 k
Is this ok [y/N]: y
Downloading Packages:
(1/2): ocaml-curses-devel 100% |=========================|  39 kB    00:00     
(2/2): ocaml-curses-0.1-7 100% |=========================|  56 kB    00:00     
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing: ocaml-curses                 ######################### [1/2] 
error: failed to stat /home/rjones/.gvfs: Permission denied
  Installing: ocaml-curses-devel           ######################### [2/2] 

Installed: ocaml-curses-devel.i386 0:0.1-7.20020319.fc9
Dependency Installed: ocaml-curses.x86_64 0:0.1-7.20020319.fc9
Complete!

# rpm -qa | grep ocaml-curses
ocaml-curses-devel-0.1-7.20020319.fc9.i386
ocaml-curses-0.1-7.20020319.fc9.x86_64

Note that the native code compiler can't find curses:

$ cat test.ml
open Curses ;; initscr ()
$ ocamlc -I +curses mlcurses.cma test.ml -o test
$ ocamlopt -I +curses mlcurses.cmxa test.ml -o test
Cannot find file mlcurses.cmxa	    	    <---- broken!

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v