Build reference time and build sessions

Understand the build reference time and build sessions.

As your build progresses, other developers can continue to work on their files and might check in new versions of elements that your build uses. If your build takes an hour to complete, you do not want build scripts executed early in the build to use version 6 of a header file and scripts executed later to use version 7 or 8. To prevent such inconsistencies, clearmake locks out any version that meets both of these conditions:

• The version is selected by a configuration specification rule that includes the LATEST version label.
• The version was checked-in after the time the build began (the build reference time).

This reference-time facility applies to checked-in versions of elements only; it does not lock out changes to checked-out versions, other view-private files, and non-MVFS objects. clearmake adjusts for time discrepancies between system clocks on different hosts in a network (clock skew).