Architecture woes with libusb-static

I’ve been trying to debug a problem with my Dell Alienware m18x ((I’m actually not a gamer.  The m18x was the one of the few options out there that offered support for 32GB of memory in a laptop.  Sure, the battery lasts for less than an hour, but it’s handy for virtualization demos.)).  In order to play with the cool back-lighting, you need install alienfx-lite, which requires userspace access to USB.  That’s what libusb comes in… or at least, it should.

So far with f19, I haven’t been able to get alienfx-lite to work.  But I haven’t really devoted any time to fixing it either.  Every so often I’ll hack on it a bit, which is why I installed the other libusb packages.

# yum search libusb
updates/19/x86_64/pkgtags | 475 kB 00:00:00
======================= N/S matched: libusb =======================
Loaded plugins: langpacks, refresh-packagekit
libusb-devel.i686 : Development files for libusb
libusb-devel.x86_64 : Development files for libusb
libusb-static.i686 : Static development files for libusb
libusb-static.x86_64 : Static development files for libusb
libusbx-devel.i686 : Development files for libusbx
libusbx-devel.x86_64 : Development files for libusbx
libusbx-devel-doc.noarch : Development files for libusbx
libgusb.i686 : GLib wrapper around libusb1
libgusb.x86_64 : GLib wrapper around libusb1
libusb.i686 : A library which allows userspace access to USB devices
libusb.x86_64 : A library which allows userspace access to USB devices
libusbx.i686 : Library for accessing USB devices
libusbx.x86_64 : Library for accessing USB devices
mingw32-libusbx.noarch : MinGW library which allows userspace access to USB devices
mingw32-libusbx-static.noarch : MinGW static library which allows userspace access to USB devices
mingw64-libusbx.noarch : MinGW library which allows userspace access to USB devices
mingw64-libusbx-static.noarch : MinGW static library which allows userspace access to USB devices
pyusb.noarch : Python bindings for libusb

Name and summary matches only, use "search all" for everything.

So I went ahead an installed libusb-static and libusbx. It didn’t actually help, but I went back to work on other stuff and forgot to remove those packages.

This morning I noticed that I had a bunch of updates that needed to be installed.  But after a yum update I saw that it wanted to install a zillion i686 packages.

Having forgotten about my extra libusb packages, I had to troubleshoot what was going on.  You can exclude architectures in /etc/yum.conf, but that seemed silly.  Luckily, yum has a nice verbose option that saved the day.

# yum update -v | grep i686
TSINFO: Marking 1:libusb-devel-0.1.4-1.fc19.i686 as install for 1:libusb-static-0.1.4-1.fc19.x86_64
---> Package libusb-devel.i686 1:0.1.4-1.fc19 will be installed

A quick rpm -e libusb-static fixed the problem, and I was able to update.

So what’s up with libusb-static?  Let’s check out the spec.

# yumdownloader --source libusb-static
Loaded plugins: langpacks, refresh-packagekit
Enabling updates-source repository
Enabling rpmfusion-nonfree-updates-source repository
Enabling rpmfusion-nonfree-source repository
Enabling rpmfusion-free-updates-source repository
Enabling fedora-source repository
Enabling rpmfusion-free-source repository
libusb-0.1.5-2.fc19.src.rpm | 286 kB 00:00:01

Huh. Looks like source rpm for libusb must build libusb-static.

# rpm2cpio libusb-0.1.5-2.fc19.src.rpm | cpio -i libusb.spec
567 blocks

In looking through the spec file, I noticed the comment:

* Sun Aug 04 2013 Hans de Goede - 0.1.5-1
- Update to 0.1.5 (#965414)
- Drop unused -static subpackage

Interesting. So there is no libusb-static as of libusb 0.1.5-1. So what I think was happening is that yum couldn’t find another libusb-static to resolve the dependency that I created when I manually installed libusb-static earlier, so it fell back on the i686 architecture.

I’m not entirely satisfied with this explanation, so I might dig a little more. But as far as an example of how to troubleshoot unwanted architectures getting installed by yum for apparently no reason, it seemed like it was worth blogging about.

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