This reportedly worked in some sage-5.x version

https://groups.google.com/d/msg/sage-devel/gHlK7zmgcAg/mREDSLLeI7wJ

I suspect it might have been earlier than 5.4. The flask notebook was
introduced in 5.4 and quite a few things regressed, even though it was
tested for months.

On Wed, Jun 26, 2013 at 12:07 PM, vbraun notifications@github.com wrote:

This reportedly worked in some sage-5.x version

https://groups.google.com/d/msg/sage-devel/gHlK7zmgcAg/mREDSLLeI7wJ

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/169#issuecomment-20026120
.

Given the current state of the notebook we should just remove the attach functionality in the notebook. Can be re-added to the new notebook when it is out.

So if we don't find a fix, should we make 'attach' just work like 'load', along with a warning that this is what it's doing?

Meanwhile, not only does it do automatic reloading, it just doesn't work: if I attach a file containing

print 3
b=4

then 3 gets printed, but if I evaluate b, I get a message saying that it is not defined. If I load the file instead, then b is defined.

I would prefer to just disable it, or maybe print an error message telling the user to use load instead.

Interestingly, I don't get any errors, just that it doesn't redo stuff when I change a file - whether from DATA or on the computer's filesystem. I am changing some doc related to this, anyway, which should help a tiny bit too - see 48bd7e7 .

I strongly suspect that this is related to lazy import, as pointed out in http://trac.sagemath.org/ticket/15308#comment:3 - at any rate, I'll be trying this out to see. Edit: or maybe not, still seems to be broken in earlier versions - I can't get it to work in 5.2, though the error is quite different, a recursion depth issue.

Interestingly, anything that requires preparsing seems to be bad now.

Using sage.misc.attached_files.attached_files() shows that attaching files does indeed happen; it is just not preparsed or something - indeed, .py files "work". However, I can confirm that things don't seem to stay defined.