saturn:/home/david# apt-get install libpthread-dev libpthread2
Reading package lists... Done
Building dependency tree... Done
The following NEW packages will be installed
  libpthread-dev libpthread2
0 upgraded, 2 newly installed, 0 to remove and 303 not upgraded.
Need to get 209kB of archives.
After unpacking 537kB of additional disk space will be used.
Get: 1 ftp://ftp.debian.skynet.be testing/main libpthread2 2.0.7-2 [81.2kB]
Get: 2 ftp://ftp.debian.skynet.be testing/main libpthread-dev 2.0.7-2 [128kB]
Fetched 209kB in 1s (177kB/s)    
Selecting previously deselected package libpthread2.
(Reading database ... 43317 files and directories currently installed.)
Unpacking libpthread2 (from .../libpthread2_2.0.7-2_i386.deb) ...
Selecting previously deselected package libpthread-dev.
Unpacking libpthread-dev (from .../libpthread-dev_2.0.7-2_i386.deb) ...
dpkg: error processing /var/cache/apt/archives/libpthread-dev_2.0.7-2_i386.deb (--unpack):
 trying to overwrite `/usr/include/pthread.h', which is also in package libc6-dev
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/libpthread-dev_2.0.7-2_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
saturn:/home/david# apt-get install libpthread-dev libpthread2