Bug for previews 2.2.0

I’m using audacity version 2.2.0 installed via an update through the KXstudio repos on Ubunutu 16.04 LTS. I’m getting an error when trying to preview audacity’s fx that reads “Internal error at WaveTrack.cpp line 1423. Please inform the Audacity team at https://forum.audacityteam.org” If I “start playback” on realtime fx, it seems to work fine, but I can’t preview Audacity’s built-in fx.
here’s a screenshot:
audacity error.png

Does the problem only occur with the Equalization effect?

No, it happens with any effect that uses the “preview” feature. The ones that use "start playback’ seem to work fine.

Are you sure that it is Audacity 2.2.0 and not an alpha version?
Line 1423 of WaveTrack.cpp is just the single close bracket:

      }

Well it installed during system updates, so I don’t think it’s the alpha version. Looking at about Audacity it just says 2.2.0. Unless there’s something screwy with the KXStudio version that got pushed out.

What do you get if you enter this in a terminal:

dpkg -s audacity

Version: 2.2.0-1build1~ubuntu16.04
Depends: audacity-data (= 2.2.0-1build1~ubuntu16.04), libasound2 (>= 1.0.16), libavcodec-ffmpeg56 (>= 7:2.4) | libavcodec-ffmpeg-extra56 (>= 7:2.4), libavformat-ffmpeg56 (>= 7:2.4), libavutil-ffmpeg54 (>= 7:2.4), libc6 (>= 2.15), libexpat1 (>= 2.0.1), libflac++6v5 (>= 1.3.1), libflac8 (>= 1.3.0), libgcc1 (>= 1:3.0), libgdk-pixbuf2.0-0 (>= 2.22.0), libglib2.0-0 (>= 2.12.0), libgtk2.0-0 (>= 2.24.0), libid3tag0 (>= 0.15.1b), libjack-jackd2-0 (>= 1.9.5~dfsg-14) | libjack-0.116, liblilv-0-0 (>= 0.16.0~dfsg0), libmad0 (>= 0.15.1b-3), libmp3lame0, libogg0 (>= 1.0rc3), libportsmf0v5, libsndfile1 (>= 1.0.20), libsoundtouch1 (>= 1.9.2), libsoxr0 (>= 0.1.0), libstdc++6 (>= 5.2), libsuil-0-0 (>= 0.8.0~dfsg0), libtwolame0, libvamp-hostsdk3v5, libvorbis0a (>= 1.1.2), libvorbisenc2 (>= 1.1.2), libvorbisfile3 (>= 1.1.2), libwxbase3.0-0v5 (>= 3.0.2+dfsg), libwxgtk3.0-0v5 (>= 3.0.2+dfsg)
Suggests: ladspa-plugin
Description: fast, cross-platform audio editor
Audacity is a multi-track audio editor for Linux/Unix, MacOS and
Windows. It is designed for easy recording, playing and editing of
digital audio. Audacity features digital effects and spectrum
analysis tools. Editing is very fast and provides unlimited
undo/redo.
.
Supported file formats include Ogg Vorbis, MP2, MP3, WAV, AIFF, and AU.
Homepage: http://audacityteam.org/

Okay, I have some new info. If I create a new project file I don’t have the problem. The file that is giving me the issue was something I recorded in the previous version. If I select “save as” and save it under a different name it still has the issue. However, if I export the tracks then re-import them into a totally new project, the problem goes away.

Unfortunately it seems that whoever built / packaged that didn’t put in any information regarding who they are. Usually there is at least the name of the package maintainer and / or the name of the repository. However, it does tell us that it is probably not from an official Ubuntu repository. It’s definitely not from the Ubuntu 16.04 repository because that is still with Audacity 2.1.2 (Ubuntu – Error).

My guess is that at some time you added a PPA (possibly: Audacity Audio Editor and Recorder : Panda Jim) so that you could get a more recent version, and it has come from there.

Excellent, that could be very helpful. Would it be possible for you to make a ZIP archive of that “bad” project (the AUP file and _data folder and dependencies if any), and upload it somewhere such as dropbox or sendspace, then post a link (if you don’t want it to be public, then perhaps send me a PM with the download link).

I think it’s Panda Jim’s version. my dpkg gives the same version string.

OK, so that gives us two lines of enquiry.
If I can reproduce the problem with your ‘bad’ project, then it’s a problem in our code (Audacity should at least be able to fail gracefully even if the data is bad).
If I can’t reproduce the problem, then it’s more likely to be a problem with that particular build of Audacity, so we can then look into that.

I’m pretty sure this one is coming from the KXStudio repositories. I have those on my system for audio software.
Here’s a link to download the projects. The exact one I was working on is the one labeled 130bpm https://drive.google.com/file/d/0By_2f6m6Axl9Ymhocm1yaUdJMFE/view?usp=sharing

Thanks. It’s a bug, and easy to reproduce.
There’s also an easy workaround:

  1. Open the project
  2. Click on one of the tracks
  3. Ctrl+A
  4. Shift + Home key
  5. Ctrl + T

When you press Ctrl + T, you should see the ← arrows at the beginning of the audio tracks disappear (we have trimmed off the portion of track that is before zero).

The problem is that if the selection extends before zero, “preview” gets an invalid length, which causes it to fail.

Now I need to log the bug, then see if I can find why it is getting an invalid length.