[racket] My PLT->Racket porting experience

From: Drew Hess (drew.hess at gmail.com)
Date: Thu Mar 3 11:03:34 EST 2011

On Thu, Mar 3, 2011 at 5:09 AM, Matthias Felleisen <matthias at ccs.neu.edu> wrote:
> On Mar 2, 2011, at 11:15 PM, Drew Hess wrote:
>> Have you tried adding a teachpack that already exists while in Beginner mode, prompting the overwrite warning dialog?
> I did like this:
>  open new tab in BSL
>  select add teachpack from Language
>  select add new teachpack
>  tried three different ones:
>  -- 2htdp/batch-io -- failure, due to missing file, window pops up on top of everything
>  -- 2htdp/image -- failure, due to missing file, window pops up on top of everything
>  -- htdp/dir -- success it just installed it (probably BAD)
> Did I miss something -- Matthias

In my case, when I see the bug (and it's only on occasion, not
every time), it's because I've asked DrRacket to install a
teachpack that is already installed. Usually the warning dialog
asking if I want to overwrite the existing teachpack is displayed
on top, but sometimes it's hidden behind the main DrRacket
window. It's not clear to me that you tried that case. (If the
htdp/dir case prompted you about overwriting an existing version,
you didn't mention it.)

I don't believe I've ever experienced a case where the failed
compile dialog is not visible. I'm fairly certain that it's only
been the overwrite warning dialog, and possibly the File->Open
dialog in my Bootstrap classes with DrScheme, though I can't
recall for certain. I know that whatever dialog box it was that
was occasionally occluded in the classroom was not the
teachpack "overwrite?" dialog, because students never installed
teachpacks. (Sorry, I know that's not particularly helpful, but
that's the way these Heisenbugs go.)


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