WriteUninstaller is sometimes slow

[lamprizzle]

I've been using NSIS for a while and I feel like I'm pretty good at it, but here's a stumper.

I'm writing installers for games that range anywhere from 6 to 50 MB (before compression). I was getting reports that games were taking a long time to install, but only SOMETIMES (which is the really weird part), so I put some logs in there and found that the WriteUninstaller command was taking 3-5 minutes to complete on these long ones, whereas on a usual run it only takes 3-5 seconds. Any ideas on what would cause WriteUninstaller to SOMETIMES take so much longer to complete?

I tried looking at the source code to figure out what WriteUninstaller is doing that would sometimes be slow, but that's really difficult.

One unfortunate thing is that I'm dealing with a very lightly customized NSIS 2.06 or 2.07, which I haven't been able to upgrade, but our customizations shouldn't affect WriteUninstaller and I don't see anything in the release notes about any fix that has increased the efficiency of WriteUninstaller.

Some other things I've thought of but have no idea if they are factors:

- does the position of the WriteUninstaller call matter? Mine is about 1/3 of the way down the script and in fact occurs in a function after the Uninstall section.

- the game NSIS installer is being called by a parent NSIS installer.

- lzma compression

- we're using a customer plugin to show some HTML UI

- I use some un. functions during uninstallation.

There are a million things I could think up that could cause WriteUninstaller to be slow, but I can't figure out why it would only be slow SOMETIMES...and REALLY slow!