[Win] Set MSBUILD environment variable to avoid long-lived processes locking log files

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Brent Fulgham]

We have encountered a number of cases where long running MSBUILD processes can hold onto log files, preventing later build requests from completing.

According to:
http://stackoverflow.com/questions/3919892/msbuild-exe-staying-open-locking-files
and:
http://stackoverflow.com/questions/13510465/the-mystery-of-stuck-inactive-msbuild-exe-processes-locked-stylecop-dll-nuget

... you can control MSBUILD's launch behavior by passing a flag at startup, or setting an environment variable.

Since our build infrastructure does not launch MSBUILD directly, we should just set the environment variable:

MSBUILDDISABLENODEREUSE=1

This tells MSBUILD to terminate after the build has completed, avoiding the locked log file.

[Brent Fulgham]

See also:
http://connect.microsoft.com/VisualStudio/feedback/details/737860/msbuild-and-msbuildtaskhost-processes-proliferate-after-exiting-vs11-beta

[Brent Fulgham]

Created attachment 221194 [details]
Patch

[David Kilzer (:ddkilzer)]

Comment on attachment 221194 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=221194&action=review

r=me

> Tools/Scripts/webkitdirs.pm:1461
> +        if (!$ENV{'MSBUILDDISABLENODEREUSE'}) {

If it's not set, this may produce a benign (but annoying) error message about using an undefined value.  This check may be slightly better:

        if (!defined $ENV{'MSBUILDDISABLENODEREUSE'} || !$ENV{'MSBUILDDISABLENODEREUSE'}) {

[Brent Fulgham]

Committed r162010: <http://trac.webkit.org/changeset/162010>