external mutator breaking on osx

[ploppelop]

working:
honggfuzz -t 3 -n 1 -e pdf -i pdf/ -Q -x -- /Applications/Adobe\ Acrobat\ Reader\ DC.app/Contents/MacOS/AdobeReader ___FILE___

breaking, adobe reader unable to process the input:
honggfuzz -c ./donothing.sh -t 3 -n 1 -e pdf -i pdf/ -Q -x -- /Applications/Adobe\ Acrobat\ Reader\ DC.app/Contents/MacOS/AdobeReader ___FILE___

donothing.sh does what it says, nothing, just simulating external modification:
#!/bin/sh
cat $1 > /tmp/bla
cat /tmp/bla > $1
rm /tmp/bla

An equally useless external mutator in c causes similar problems:
int main(){return 0;}

[ploppelop]

scratch the adobereader and osx part, same issue on linux with evince as test, input to the mutator is empty before it gets to process it:

#!/bin/sh
echo external mutator invoked with $1
file $1
dst=`file $1 | awk '{ print $5}'`
file $dst
cat $1 > bla
echo nullmodification
cat bla > $1

invoked with
honggfuzz -c ./external.sh -s -t 2 -n 1 -e pdf -i pdf -Q -x -- /usr/bin/evince ___FILE___

->
external mutator invoked with /dev/fd/10
/dev/fd/10: symbolic link to /dev/shm/hfuzz.cpBN95 (deleted)
/dev/shm/hfuzz.cpBN95: cannot open `/dev/shm/hfuzz.cpBN95' (No such file or directory)
nullmodification