I tried upgrading from 2.084.1 to 2.085.0-rc.1 while Visual Studio Code was still open. The installer complained that it couldn't install C:\D\dmd2\windows\bin64\libcurl.dll with options to retry/abort.
Trying to delete the file manually revealed that it was in use by dls, presumably the D language server.
Closing VS Code and pressing retry led to successful completion of the installation.
Perhaps there is something that can be done to smoothe this out, for example
1) Tell the user to close any open editors that use dls, or
2) Signal dls to terminate temporarily, or
3) Eliminate permanent linkage of the dmd libcurl to dls. I thought dls was a separate installation, I don't understand how it comes to link to dmd's libcurl.
Thanks,
Bastiaan.