It has stopped detecting my Nikon D5100 as well. Haven't tried to rebuild though to see if this solves the problem.

It's already been built against the latest gphoto2. Does rebuilding it in a clean chroot fix it as well?

I rebuilt and installed the following packages and everything is now working fine. I didn't use a clean chroot. Just my regular system.

digikam-4.5.0-2-x86_64.pkg.tar.xz kipi-plugins-4.5.0-2-x86_64.pkg.tar.xz libkface-4.5.0-2-x86_64.pkg.tar.xz libkgeomap-4.5.0-2-x86_64.pkg.tar.xz libkvkontakte-4.5.0-2-x86_64.pkg.tar.xz libmediawiki-4.5.0-2-x86_64.pkg.tar.xz

Unfortunately, if you don't build in a chroot, we can't tell if the maintainer rebuilding will fix it or not.

I have exactly the same problem with a Canon PowerShot SX200. The latest version that was working corretly was
digikam-4.4.0-1-x86_64.pkg.tar.xz
libkgeomap-4.4.0-1-x86_64.pkg.tar.xz
libkface-4.4.0-1-x86_64.pkg.tar.xz

@xxarch, so if you rebuild digikam in a clean chroot, does it work? Just grab the build files, install dev-tools, and run extra-x86_64-build.

@Scimmia: I will try to find some time to do this within the next days. However, I am quit new to arch and I have to look for some tutorials on the build-proces, first. Can you reccomend such a tutorial?

I've done the same thing like Alex. Now I can import photos from my canon EOS 400D. But I have additional problems with import process. I don't see any thumbnails (nor for jpeg and nor for RAW) and metadata for RAW.

@Tomas I had the problem with the thumbnails with digikam 4.3. and 4.4. It was solved in 4.5. Here is the relevant bug https://bugs.kde.org/show_bug.cgi?id=338407. I don't have the problems you mention...
@Doug If I have some time in the weekend I'll try the clean chroot rebuild.

@Alex but I had no problems with previous versions. Jpeg had had always thumbnail.

@Tomas Then the above fix might have broken something for you. I can't tell for sure.

I did a rebuild of the package. Please test if the packages you can download at [1] or [2] fix this.

[1] https://dev.archlinux.org/~ronald/test/x86_64/
[2] https://dev.archlinux.org/~ronald/test/i686/

@Ronald: I tried the packages from https://dev.archlinux.org/~ronald/test/x86_64/. It is exactly the same problem as before: Digikam sees that there is a camera connected but it cannot get the pictures (Canon PowerShot SX200).

@Ronald I just tried your x86_64 packages. Again digikam can't connect to my camera.

In that case I suppose it is missing a buildtime dependency.

@axel: Can you run namcap on the package you did build locally without a chroot and see if it links to anything that isn't a dependency of digikam and could be related to this issue?

Here is the output of namcap -i

http://pastebin.com/amRH4qMR

I played a bit around. This is interesting:

1.) rebuild digikam-4.5.2 from sources on my regular system using "makepkg" -> works as expected
2.) rebuild digikam-4.5.2 from clean chroot using extra-x86_64-build -> cannot connect to camera

The difference is in the package digikam-4.5.0-2-x86_64.pkg.tar.xz. When swapping between the two compiled packages by only reinstalling digikam-4.5.0-2-x86_64.pkg.tar.xz from one of the two builds I get either a working digikam or a non-functional digikam.

Do you have any further ideas on the cause of this difference?

It seems there is an issue with the shared library dependencies.
Here is a diff of "ldd /usr/bin/digikam" outputs between my build without chroot and the official build, these libraries are missing :

libexif.so.12
libgphoto2_port.so.10
libgphoto2.so.6
liblcms.so.1
libltdl.so.7

Thanks. I'll have a closer look at the build process tomorrow to find out what build dependency is missing. Hopefully my camera doesn't work as well, would make it a bit easier to test.

Possibly related?  FS#43001 

No,  FS#43001  is not related.

Gphoto2 support wasn't build because of a missing buildtime dependency to libusb-compat, so it seems. I'll get some packages up for testing soon.

please test the packages in [testing]

They are working for me. :)