Summary

Symptoms

Attempting to use the SRCDIR variable in an InstallScript custom action after a first time install (such as a minor upgrade) results in a path that does not point to the location of the MSI package, but instead resolves to a path in the temp folder.

Cause

This is expected behavior for Basic MSI projects. The InstallScript engine uses the Windows Installer API MsiGetSourcePath to determine the resolved value for SourceDir, which SRCDIR is then set to. However, after a first time install, attempting to resolve SourceDir will cause a prompt for the original source media, which is typically not desired when there is no need for the media. If the InstallScript engine determines that the setup is not running in a first time install, it does not attempt to get a value for SourceDir. The SRCDIR variable points to the runtime location of the compiled setup.inx (typically a temp folder location) when SourceDir is not resolved.

Note that InstallScript and InstallScript MSI projects do not exhibit this behavior as the SRCDIR location is stored in the InstallScript log file.

Resolution

The SRCDIR variable should only be used in custom actions that run during a first time install. During a maintenance scenario, such as a minor upgrade, the SETUPEXEDIR property can be used to determine the path to the source media when launching from setup.exe.

Additional Information

More information can be found in the following articles:

• SRCDIR
• See Realted KB Articles section for article Q105487, PRB: SourceDir and SRCDIR Resolve to a Location Under the Temp Directory
• ResolveSource Action.

Related KB Articles