Note that on machines that support multiple system types, EACH system type gets the full number of build slots, which is almost certainly not what we want.
SA5ZZ3I4SPTEEPJ5YE6JJA2DUPD4UTTC3APBNQL6XZW6PXYJRP6QC
LZO3C2KIACZ3HN72RBGWWIT5ED4RJMYKI3SAHXT6RIUPHDFL3STQC
DQD7JMSUAPXKASPXUDXY4LCE6QCAZSGWNQYTOKNIQE6RRSRP4KGAC
7YBYT2LQML2PKEO6UO4444AGSASS664UCDXW2YO3ALB7THQHCEBQC
NREF6YOAKK2QVNXGU7WHD3KSDNCCIAQW3GQ5KOANEXFBWDPUHWXAC
ECBA3GQOGTF73Y7A5EFUXZ5PDIZ5NPJM3WMOUJTE3AEK2PZQX3MQC
TWVSALRLHGSY6SHLMLT53K2A5SUCPU3SNFPZ2KWYOLDQUJBSZ2OAC
# How many extra builds can we start?
(my $systemTypeInfo) = $db->resultset('SystemTypes')->search({system => $system->system});
my $maxConcurrent = defined $systemTypeInfo ? $systemTypeInfo->maxconcurrent : 2;
my $extraAllowed = $maxConcurrent - $nrActive;
my $extraAllowed = $maxConcurrent{$system} - $nrActive;