Signature Bug

Please fill out these questions for all feature requests and bug reports. If you're requesting a feature, please let us know why this feature is important or useful, not just what it should do post it in the Feature Requests category.

  1. What browsers show this problem?
  2. Please share an example project (if possible).
    First, I was trying to make Generators in Snap! just like my Pinky Promises project for Promises. I made a reporter block that constructs a new generator and there is an upvar to make the yield reporter work, but I ended up making it a command because I couldn't figure out a difference between the two values (reported and upvar) or how to clear the upvar but still make it work inside the body.
    tl;dr: While I was working on a project, I turned a reporter into a command and saw the bug.
    I made a project that experimented with the bug: signature bug test
  3. Describes the steps to reproduce this issue.
    Simply make a reporter or predicate, then change it to a command.
  4. What does Snap! currently do?
    Watch this 3.5-minute video to find out.
  5. What should Snap! do instead?
    Not have a second signature that turns into the final block after a reload.

Is this bug a security concern? If so, please do not post security concerns directly to the forum. Please email us at Thank you!

I actually know another way to produce that bug, make a reporter, change the reporter to a command, apply, and you might see it. I found the bug in snap 5, but couldn't reproduce it unless I used a large project, but now it's easier to do it in snap 6. idk why I never mentioned it until now.

um, I found even more bugs, with this, like, a block definition as an input (wut?). Here's me playing around with it (and causing it) Youtube: Drive:

Hmm, I wonder whether this is related to the new reporter-must-report feature complained about in another thread...