Update: I did cvs and that went ok. Now it reports this:

=> Applying pkgsrc patches for poppler-0.5.3
**************************************
Ignoring patch file 
/usr/pkgsrc/print/poppler/../../print/poppler/patches/patch-aa: invalid 
checksum
**************************************
**************************************
Ignoring patch file 
/usr/pkgsrc/print/poppler/../../print/poppler/patches/patch-ab: invalid 
checksum
**************************************
ERROR: Patching failed due to modified or broken patch file(s):
ERROR:  /usr/pkgsrc/print/poppler/../../print/poppler/patches/patch-aa
ERROR:  /usr/pkgsrc/print/poppler/../../print/poppler/patches/patch-ab
*** Error code 1

What can I do about that?