lrzip freezes on low memory

[Nils Toedtmann]

We use lrzip to compress large logs with an hourly cronjob. The server is sometimes short of memory. Occasionally lrzip freezes. Usually it just hangs doing nothing, "strace -p $PID" just showing "WAIT(...". Every now and then it's consuming 100% CPU doing this ad infinitum:

---<SNIP>---
mmap(NULL, 776081408, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory)
mmap(NULL, 775950336, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory)
mmap(NULL, 775950336, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 ENOMEM (Cannot allocate memory)
brk(0x2fb42000) = 0x1742000
---<SNIP>---

Instead, lrzip should exit with a non-zero exit code so the situation can be dealt with properly.

He would prefer to use lrzip to archive our data, but because of this bug we had to revert back to gzip/bzip2 :-(

This is lrzip 0.608-1 on Ubuntu 12.04.5 (precise)