Remove Version pin to Dafny 2.3.0

[fabianhauser]

As part of #66 , @kailingP added 2d7fc93 which pins the downloaded Dafny version to 2.3.0. This should be reverted as soon as Dafny 3.0.0 is stable.

[RustanLeino]

Hi @fabianhauser @kailingP . Sorry, I got here a bit late.

From what I'm hearing, the problem with #66 was that the .zip files can't be properly unzipped. Do we know why this is? Is it possible that, when creating them, I used a zip utility that doesn't work properly? That's a problem I need to fix, but I don't understand enough of what's going wrong to know how to fix it. Any help appreciated.

Ironically, I had published the pre-release (actually, in the last three days, I did a pre-release 0, then a pre-release 0a which included two missing DLLs, and then a pre-release 1 which fixed a problem with calling the C# compiler on some platforms) to give easy access to a Dafny version newer than 2.3.0. This is why I marked didn't mark the new release as "prerelease" on github.

It's always nerve-racking to do a new release. Would it be possible for the VS Code plug-in to offer a choice of which Dafny release to use? Then, someone could revert to 2.3.0 if the breaking changes in 3.0.0 caused a problem. And it would allow us to really do a "pre-release" (in the github sense) of a new release, and by manually selecting such a pre-release in VS Code, we could try it out before marking it as "stable" on github and having VS Code update the whole world to it?

[kjx]

As I said on #66 the current version seems to work now.

As well as students on VScode we have people using their own installations, plus installations in the lab, plus two different marking systems (one for quick formative quetions, one for assessed projects) that all depend on particular versions of Dafny. Dafny verifiability doesn't seem to be monotonic - there are some things 3.0.0 will verify that 2.3.0 won't - and vice versa - but either way could cause students problems, if e.g. they are running 3.0.0 but our marking system

So one way or another, it would be great to have positive control over which version of Dafny people are running - even if that's just a "stable" (2.3.0) vs "latest" (3.0.0) switch.

[fabianhauser]

From what I'm hearing, the problem with #66 was that the .zip files can't be properly unzipped. Do we know why this is? Is it possible that, when creating them, I used a zip utility that doesn't work properly?

I've taken a quick look at it, but could not figure out what the problem is with the zip files. Maybe it has something to do with the Node-Library that is used here.

Would it be possible for the VS Code plug-in to offer a choice of which Dafny release to use?

Yes, that would be great; currently, the way to achieve that is manually downloading and configuring the paths to the version. I plan to take a look at a version manager with the major new release™ that's currently waiting on some spare time on my side...

[kjx]

could not figure out what the problem is with the zip files. Maybe it has something to do with the Node-Library that is used here.

I think that's quite likely, given that I don't think anyone's had problems unzipping the archive using a zip command on anything.

currently, the way to achieve that is manually downloading and configuring the paths to the version

which is OK really - although it's also good to have Dafny downloaded and installed within the VSC extension, that's not something we'd really want to lose either. The other thing I still don't understand, and which seems to affect Macs most, is that even deleting the whole .vscode directory didn't erase the memory of the extension completely. The 0.18.0 installation was able to clean stuff up in a way that uninstalling or reinstalling did not.

[tnelson]

Following up: is it now possible to use Dafny 3.0.0 (prerelease) via this extension?
I've tried locally reverting the change in 2d7fc93 to stringResources.js so Installer.ReleaseURL points to latest, rather than 2.3.0, but at that point I'm seeing the freeze at "Extracting Dafny : (4%) ". This is after reinstalling, etc.

[fabianhauser]

Hi @tnelson

@camrein is currently implementing the support for Dafny 3.0, you can try the current state in the VSCode Marketplace with the Dafny (Preview) extension. It is not yet feature complete, but if you notice any bugs, feel free to open an issue here.