Separate MPS caches for different MPS distributions based on the same MPS major version

Between MPS major versions, the MPS global caches are nicely separated (e.g. for MPS 2017.1, the cache directory is $HOME/.MPS2017.1 and for MPS 2017.2, the cache directory is $HOME/.MPS2017.2, where $HOME is your home directory, e.g. C:\Users\<yourusername> on Windows or /home/<yourusername> on Linux). Sometimes, there are reasons why you would want to change the cache for a specific MPS distribution on your filesystem. Some of these reasons are:

  • Run different distributions or RCPs of MPS that have the same major version at the same time on your machine
  • Separate two MPS global caches (e.g. a cache for production in some project you work on and another cache for a course you have to give tomorrow), so they don’t interfere with each other.
  • Be able to open two modules (language or solution) with the same name/ID, without the two getting intermixed in the global cache (or MPS thinking that one has already been loaded, making the other read-only).

By default, the MPS cache-directory for an MPS major version called <version> (located under your $HOME directory) is .MPS<version>, e.g.: .MPS2017.2.

You can change this default location by adding a line like this in your vmoptions (for Windows, it’s located under your <mps installdir>\bin\mps64.exe.vmoptions):


This would lead to the MPS that you run from <mps installdir> to maintain a cache directory called .MPS-MYOWNTHING in your $HOME directory.


One Reply to “Separate MPS caches for different MPS distributions based on the same MPS major version”

  1. It may be good to know that nowadays the paths selector is not set anymore in the vmoptions file, but rather in the launcher (e.g. mps.bat). It is now set on the line:

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