Bug#924291: netrek-client-cow: build can loop indefinitely on failure

[Helmut Grohne]

Source: netrek-client-cow
Version: 3.3.1-1
Severity: serious
Justification: breaks build infrastructure

When mkkey fails to run, netrek-client-cow has a very bad failure mode.
It loops until mkkey succeeds:

| until ./mkkey key.cow.linux "Client Of Win" "automatic packaged key" "quozl at us.netrek.org" "netrek.org/files/COW/" "inl,standard2"; do sleep 1; done

When mkkey fails reliably and produces output, this causes the build to
run indefinitely as sbuild only abort a build that has no output for a
prologned time. This behaviour can make buildds and QA infrastructure
hang.

I suggest using a bounded loop and failing hard after a number of
attempts. That's a very simple solution to the problem at hand. For
instance:

| attempts=32; until ./mkkey ...; do attempts=$((attempts - 1)); test $attempts -le 0 && exit 1; sleep 1; done

Furthermore I question why a key should be created at build time and
then be distributed to consumers of the package. That seems to run
counter to the concept of a "key". If the key is to protect anything, it
must not be public. Maybe the best course of action would be not
creating this key at all during build.

Helmut