Travis-CI MacOS builds (denoted
.travis.yml) emerged from beta in April 2013 using cloud-based Mac hardware.
As this service became popular beyond iOS developers using it for Objective C builds, the amount of free service offered for MacOS builds became increasingly constrained.
Free Travis-CI.org users are concurrency constrained to two MacOS instances and five Linux instances. MacOS builds count against the total concurrency limit of five for free Travis-CI.org users.
The Travis-CI status panel shows that the MacOS backlog is typically non-zero, and is in the hundreds or thousands during many hours of a 24-hour days. Meanwhile, the Linux backlog typically stays at or near zero.
The practical impact of this is that MacOS builds commonly take 20+ minutes to start, sometimes even several hours to start, making troubleshooting
osx very difficult.
Paid Travis-CI.com customers on the other hand should experience short wait times of a minute or so for