---
layout: post
title: "Digikam, dependencies, and building KDE libraries"
date: 2015-09-05 12:49:51 +0200
comments: true
categories: 
---

Context
=======

I have a very basic KDE environment, just enough to be able to run
Digikam. Anytime I try to delete a photo, I get an error message:

```plain
Could not start process
Unable to create io-slave: klauncher said: Unknown protocol 'trash'.
```

Oh, well. So I guess the FreeBSD port for Digikam fails to list a
required dependency.

Building KDE workspace
======================

A little grep'ping in port plists hints that the missing dep
might be x11/kde4-workspace. Alright, let's build that.

```plain Build log
[...]
===>   Registering installation for kfilemetadata-4.14.3_2 as automatic
pkg-static: Unable to access file /var/ports/work/usr/ports/sysutils/kfilemetadata/work/stage/usr/local/lib/libkfilemetadata.so.4.14.3: No such file or directory
*** Error code 74
```

The kfilemetadata fails to install. That file is indeed missing; the staging area
does however contain a libkfilemetadata.so.4.14.2. So why does the source package
of 4.14.3 generate a 4.14.2 library?

A trip in KDE-build-land
========================

Answer: the library version is not set by the package itself, it comes from a
default value from:
o

```plain /usr/local/share/apps/cmake/modules/KDE4Defaults.cmake
set(GENERIC_LIB_VERSION "4.14.2")
```

Where does this come from?

```plain
$ pkg which /usr/local/share/apps/cmake/modules/KDE4Defaults.cmake
/usr/local/share/apps/cmake/modules/KDE4Defaults.cmake was installed by package kdelibs-4.14.2_5
```

Conclusion: the build dependency for kfilemetadata should list the exact same version of
kdelibs, or the port won't build.

So, we now need to upgrade kdelibs in order to be able to build kfilemetadata, which
is a dependency of kde4-workspace, which is an unlisted dependency of Digikam.

Rebuilding kdelibs from sources involves a portmaster operation that will on this
system rebuild a few hundred depedencies, so doesn't sound like an attractive option
(too big a build to babysit, with likely hiccups on the way, and in any case too
much of an earthquake with so many ports being updated at once.

Upgrading kdelibs
=================

Let's instead upgrade kdelibs from binary package, and hope for the best:

```plain
# pkg install -f kdelibs
```

This breaks because the binary package depends on a newer libpng, so let's upgrade this one,
keeping the old shared lib intact just in case.

```plain
$ digikam 
/usr/local/lib/libpng16.so.16: version PNG16_0 required by /usr/local/lib/libkhtml.so.5 not defined
```

Strange that libpng 1.6.16 does not have version 16... Sigh... OK, upgrading from png-1.6.16
to png-1.6.18 appears to fix the problem. Back on track...

Back to KDE Workspace
=====================

Side note: hey, couldn't I just install kde-workspace from packages as well? Well,
for some reason pkg wants to remove my TeXlive install, and upgrade two dozen other
packages, so thanks, but no thanks. (I would have gone for it were it not for the
removal of TeXlive. But that's too much breakage to fix downstream.)

Now Digikam displays its splash screen and starts initializing, then segfaults.
Hell, I'll have to bite the bullet and upgrade a few hundred packages from ports. :-(