NOTE: Sometimes, reporters mark issues as New without being confirmed by a Mozillian or Community Member. Read carefully to see if it needs confirmation to remain New or it needs to be changed back to Unconfirmed until it can be reproduced

NOTE: If you are sure that a Feature Request or an Enhancement is a valid one, you could also set its status to NEW, but usually this is the component owner's job.

<Ask additional details regarding environment if needed>

Is this still reproducible on your end ? If yes, can you please retest this using latest FF release and latest Nightly build (https://nightly.mozilla.org/) and report back the results ? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (https://goo.gl/PNe90E).

I have tested your issue on latest FF release (version), latest Nightly build (buid ID) and managed to reproduce it. I have <what and how it has been tested>

Reproducible also on: version + build ID (if necessary)

1. Based on Comment <comment number> from the reporter, changing status to RESOLVED WORKS FOR ME.

For the cases when reporter did not added requested info and we cannot reproduce (bug has explicit STR):

2.Considering the fact that I cannot reproduce this and the fact that the reporter did not answered to my/<name> request until now, I will mark this as Resolved - Worksforme.

If anyone can still reproduce it, feel free to reopen the issue and provide more information.

If anyone can still reproduce it on latest versions, feel free to reopen the issue and provide more information.

However, I am assigning a component to this issue in order to involve the development team and get an opinion on this.

There are no crash reports in the last 7/14/28 days in the crash signatures provided, therefore closing this bug as Resolved: Works for me. Please reopen the bug if the crash still reproduces and provide more information.

Information on the tool is available at http://mozilla.github.io/mozregression/. Please don't hesitate to contact us if you encounter any problems.

Use MozRegression to find where the fix occurred - If time permits, probably lower priority

What you can do is to download the installer form "http://archive.mozilla.org" and have an archive manager program like "7zip" installed (freeware program). Open the folder where the installer was downloaded and right click it in order to use 7zip program to extract the installer. After doing that, you will have a folder where the Firefox build is extracted and from where you can start the actual version without installing it. As a suggestion use the command window to open it with a different profile and with no remote setting.

It will prompt the current user for the credentials of the user that installed the software. So, if the administrator installed the software, and the software is available also on a 2nd user desktop, updating the software should and will request the administrators password in order to update it. If the software that you are trying to update was installed by the current user on which you are logged in, it will require the current user credentials in order to update it.

In order to do this, you'll need to install a couple of things before starting the tool. Here are the steps needed depending on OS needed for testing:

       • Mac OS X (10.11 only, for older versions see next bullet)

In order to use MozRegression tool on Mac OS X 10.11, you will need to perform some additional steps than on other Mac OS versions. One of the steps is installing a virtual environment trough python so you won't get any conflicts between python and MozRegression.

Here are the complete steps to install and use MozRegression trough Virtual environment:

1. First, you will need to open a Terminal window and enter the following command "sudo su" (without quotes). You will be prompted to insert the PC user password (the password used for logging in on the Mac OS user). If you don't see the characters you are entering, don't worry, they are entered but due to security are hidden. After entering them press the "Enter" key.
2. After credentials are confirmed it's time to install the Python 2.7 component by entering the next command "sudo easy_install pip".
3. Next you will need to install the virtual environment using the next command "sudo pip install virtualenv".
4. After the virtual environment was installed, you will need to provide a directory name for the virtual environment using
"virtualenv <directory_name>" command (eg: "virtualenv mozregression" will create the environment folder under your current profile).
5. Next you will need to activate the environment from a file that was created in the environment folder using "source /Users/profile_name/folder_name/bin/activate" command (eg: "source /Users/pauloiegas/mozregression/bin/activate").
6. You will notice that your command line is now changed into "(mozregression) < code >". Now you will need to install the mozregression tool into the virtual environment using "pip install mozregression" command.
7. After the installation is completed, you can check if everything is ok using a simple command like "mozregression -h" to see if the tool help is displayed (if not, you did something wrong along the way).
8. After doing this you are ready to start digging into builds. You can do that by using the next two commands "mozregression --good <build_date>" (eg: mozregression --good 2014-12-31) when you only know the build when it was ok, or "mozregression --good <build_date> --bad <build_date>" (eg: mozregression --good 2014-12-31 --bad 2015-12-31) when you know both a good build and a bad build.
9. Mozregression will start downloading builds and open them to test your issue. After testing the issue you must validate the build with "good" or "bad". The tool will continue to download and open builds until the search is narrowed down to two builds and will throw a "Pushlog link" that you will need to provide in the bug comment together with any additional information that we consider to be helpful.
10. You will need to deactivate the virtual environment after you complete the regression using "deactivate" command that will return you to the normal command line.
11. REMEMBER ! The environment must be activated each time when you want to use the Mozregression tool.

       • Mac OS X (10.10 and under)

1. First, you will need to open a Terminal window and enter the following command "sudo su" (without quotes). You will be prompted to insert the PC user password (the password used for logging in on the Mac OS user). If you don't see the characters you are entering, don't worry, they are entered but due to security are hidden. After entering them press the "Enter" key.
2. After credentials are confirmed it's time to install the Python 2.7 component by entering the next command "sudo easy_install pip".
3. After the Python installation is finalized, you'll need to install the latest version of mozregression by entering the next command "sudo pip2 install -U mozregression"
4. After doing this you are ready to start digging into builds. You can do that by using the next two commands "mozregression --good <build_date>" (eg: mozregression --good 2014-12-31) when you only know the build when it was ok, or "mozregression --good <build_date> --bad <build_date>" (eg: mozregression --good 2014-12-31 --bad 2015-12-31) when you know both a good build and a bad build.
5. MozRegression will start downloading builds and open them to test your issue. After testing the issue you must validate the build with "good" or "bad". The tool will continue to download and open builds until the search is narrowed down to two builds and will throw a "Pushlog link" that you will need to provide in the bug comment together with any additional information that we consider to be helpful.

If something has been missed you can find all the mentioned information also at this link -> http://mozilla.github.io/mozregression/quickstart.html.

NOTE: MozRegression tool is not perfect and will throw some errors on some old builds. If it is your case, please refer to my other lesson from above this where you have information on how to manually create the "Pushlog link" for the found builds.

If you encounter some errors involving Python while trying to use MozRegression on Mac OS, please look at the next lesson to resolve this issue.

1. First, you will need to open a Terminal window and enter the following command "sudo su" (without quotes). You will be prompted to insert the PC user password (the password used for logging in on the Mac OS user). If you don't see the characters you are entering, don't worry, they are entered but due to security are hidden. After entering them press the "Enter" key.
2. After credentials are confirmed it's time to install the Python 2.7 component by entering the next command "sudo easy_install pip".
3. Next you will need to install the virtual environment using the next command "sudo pip install virtualenv".
4. After the virtual environment was installed, you will need to provide a directory name for the virtual environment using "virtualenv <directory_name>" command (eg: "virtualenv mozregression" will create the environment folder under your current profile).
5. Next you will need to activate the environment from a file that was created in the environment folder using "source /Users/profile_name/folder_name/bin/activate" command (eg: "source /Users/pauloiegas/mozregression/bin/activate").
6. You will notice that your command line is now changed into "(mozregression) < code >". Now you will need to install the mozregression tool into the virtual environment using "pip install mozregression" command.
7. After the installation is completed, you can check if everything is ok using a simple command like "mozregression -h" to see if the tool help is displayed (if not you did something wrong along the way).
8. You will need to deactivate the virtual environment after you complete the regression using ""deactivate" command that will return you to the normal command line.
9. REMEMBER ! The environment must be activated each time when you want to use the Mozregression tool.

1. First, you will need to download and install Python 2.7 from ActiveState website (http://www.activestate.com/activepython/downloads).
2. After installing Python you will need to open a command prompt window and enter the next command "pip install -U mozregression".
3. After doing this you are ready to start digging into builds. You can do that by using the next two commands "mozregression --good <build_date>" (eg: mozregression --good 2014-12-31) when you only know the build when it was ok, or "mozregression --good <build_date> --bad <build_date>" (eg: mozregression --good 2014-12-31 --bad 2015-12-31) when you know both a good build and a bad build.
4. MozRegression will start downloading builds and open them to test your issue. After testing the issue you must validate the build with "good" or "bad". The tool will continue to download and open builds until the search is narrowed down to two builds and will throw a "Pushlog link" that you will need to provide in the bug comment together with any additional information that we consider to be helpful.

If I missed something you can find all the mentioned information also at this link -> http://mozilla.github.io/mozregression/quickstart.html.

NOTE: MozRegression tool is not perfect and will throw some errors on some old builds. If it is your case, please refer to my other lesson from above this where you have informations on how to manually create the "Pushlog link" for the found builds.

1. First, you will need to open a Terminal window and enter the following command "sudo su" (without quotes). You will be prompted to insert the PC user password (the password used for logging in on the Linux user). If you don't see the characters you are entering, don't worry, they are entered but due to security are hidden. After entering them press the "Enter" key.
2. After credentials are confirmed it's time to install the Python 2.7 component by entering the next command "sudo apt-get install python-pip". You will be asked if you are sure you want to install it and you must confirm by entering "y" key and confirm the choice after.
3. After the Python installation is finalized, you'll need to install the latest version of mozregression by entering the next command "sudo pip2 install -U mozregression"
4. After doing this you are ready to start digging into builds. You can do that by using the next two commands "mozregression --good <build_date>" (eg: mozregression --good 2014-12-31) when you only know the build when it was ok, or "mozregression --good <build_date> --bad <build_date>" (eg: mozregression --good 2014-12-31 --bad 2015-12-31) when you know both a good build and a bad build.
5. Mozregression will start downloading builds and open them to test your issue. After testing the issue you must validate the build with "good" or "bad". The tool will continue to download and open builds until the search is narrowed down to two builds and will throw a "Pushlog link" that you will need to provide in the bug comment together with any additional information that we consider to be helpful.

If I missed something you can find all the mentioned information also at this link -> http://mozilla.github.io/mozregression/quickstart.html.

NOTE: MozRegression tool is not perfect and will throw some errors on some old builds. If it is your case, please refer to my other lesson from above this where you have information on how to manually create the "Pushlog link" for the found builds.

1. First, you'll need to manually find a bad Nightly build date by downloading builds from http://ftp.mozilla.org/ . For quick testing I suggest to download zip-ed builds, extract them and use the command window / terminal to launch the build with "-no-remote" and "-p" commands. In Windows you just need to navigate to the extracted folder, hold Shift + right click on free area of the window, then click the "Open command window here" option. After the cmd is opened, write "firefox -no-remote -p" and hit "Enter" key. This will open a separate instance of Firefox with the profiler window, where you can choose to use a no update profile created before (will not update an older version of FF). After that, just test the build and see if it's reproducible. On Mac OS, you can install the build, and in order to open it with a no update profile, you need to navigate ti instalation directory manually from terminal window (/Applications/FirefoxNightly.app/Contents/MacOS/firefox -no-remote- -p)

2. After you find a bad build, the next step would be to open a command window and start using mozregression by typing "mozregression --bad year-month-day --good year-month-day --find-fix". You need to be sure that bad build is older than good build, otherwise this won't work.Usually the good build would be the latest Nightly so use that date, otherwise it's a regression issue that needs to be treated like in previous lessons. The "--find-fix" atribute in mozregression does exactly what bisect does in normal usage. It searches for the exact push that fixed the issue. In most of the cases you end up with only one issue that you can provide to the reporter of your triaged issue as more information.

Windows:

1. First you'll need to have a good build date and a bad build date as for any other regression window checked.
2. Open a Command Prompt window and observe the path displayed. It should be something like "C:\Users\profile_name>"
3. Start Firefox with the profiler and create a test profile if you don't have one (you will need a specific name in order to find it faster).
4. Open "My Computer" and navigate to your OS partition in Users\<your_profile_name>\AppData\Roaming\Mozilla\Firefox\Profiles\<created_profile_name>\ folder. Remember that "AppData" folder is only displayed when "Show hidden files" option is checked.
5. Click the window address bar in order to view the complete path and copy it from the end to start, leaving behind only the already existing path from command prompt.
6. With the good and bad build dates, write a command like "mozregression --good year-month-day --bad year-month-day --profile \AppData\Roaming\Mozilla\Firefox\Profiles\<created_profile_name>\" (eg: C:\Users\paul.oiegas>mozregression --bad 2015-06-06 --good 2016-02-23 --profile \AppData\Roaming\Mozilla\Firefox\Profiles\w9gzt0rd.testrelease2).

Mac OS X:

The steps are the same, only the path is different. Profile folders are in one of these locations:

   ~/Library/Application Support/Firefox/Profiles/<profile folder>
   ~/Library/Mozilla/Firefox/Profiles/<profile folder> 

The tilde character (~) refers to the current user's Home folder, so ~/Library is the /Macintosh HD/Users/<username>/Library folder. (--profile=/Users/pauloiegas/Library/Application\ Support/Firefox/Profiles/rg0ayjkt.PrintTESTn)

After this steps, you are all set and can perform the regression range as normal. By using the "--profile <path>" attribute, each downloaded build trough mozregression, will use the same profile and store data on it. This flow can be used also with "--find-fix" attribute as mentioned in the above lesson by adding it after the default command contents and the "--profile <path>" one (eg: C:\Users\paul.oiegas>mozregression --bad 2015-06-06 --good 2016-02-23 --find-fix --profile \AppData\Roaming\Mozilla\Firefox\Profiles\w9gzt0rd.testrelease2).

If you encounter a regression bug on Android OS, you will need to perform a couple of steps in order to be able to run MozRegression tool on an Android device. Here are the steps that you need to follow on Windows in order to find a regression range. Will update the lesson with steps also for Mac OS and Linux after I will find how to set the "Environment variables" on each of them.

1. Install the latest Android SDK with Android Studio from (http://goo.gl/OPyvqU ) or only the command line tools from next link Windows - http://dl.google.com/android/installer_r24.4.1-windows.exe Android studio contains also the SDK needed for this to work, but it's also a coding and debugging software for android with a friendly user interface. But if you don't need this, you can install just the command line tools.

2. Install the latest Java JDK from Oracle website (http://goo.gl/rknzzs). It should be straight forward, no extra settings needed.

3. For best results install PDA Net software in order to have most of the Android devices drivers installed (http://pdanet.co/). However, there are cases when this software does not contains the drivers for all the new devices. For example there have been reported that LG G4 driver is not contained. In this case you will have to manually search and install the driver for your device.

4. Next step is a bit trickier and you must pay attention at what changes you are doing. - First you must navigate to "System" window in Windows (right click on My Computer + Proprieties). - Chose the "Advanced System Settings" option from left side of the window, and from the bottom of the displayed window select "Environment Variables" option. - In the "Environment Variables" window, you need to add first a new "System variable". Click the "New..." button and add "ANDROID" for variable name and in the variable value field, you need to add the path where you have installed the SDK (eg: C:\Users\profile_name\AppData\Local\Android\sdk where "profile_name" is usually your PC user name). After that click "Ok" button to save the variable. - Next step would be to edit the "Path" system variable (double click on it), and add two new strings. First is "%ANDROID%\tools\" and second "%ANDROID%\platform-tools\". Hit "Ok" button for every window and you are all done with this step.

5. Next you will need to install MozRegression tool by using the steps from the above lessons learned or to use the MozRegression GUI that you can download from here (https://goo.gl/DyFFok).

6. On your Android device be sure you have the "Developer options" enabled. Tap multiple times on "Build number" area in "About device" section of device "Settings" page. Return to device "Settings" main page and from the "Developer options" that are now displayed, switch to "On" the "USB debugging" option.

7. After this, you are almost good to go. Connect your Android device to the PC, run a command window (make sure you have the latest mozregression version "pip install -U mozregression") or the Mozregression GUI. For the command window mode, the only thing that is different from the PC testing is the "--app=fennec" command that you need to introduce before good & bad dates. The command will look like "mozregression --app=fennec --good 2015-05-06 --bad 2015-07-09".

Notes and Tips & Tricks:
- There are cases when the build is installed and opened instantly but there are times when the build takes a few minutes to load. Just have patience young Jedi.
- If you need to test on older Android versions like 2.3x, you need to use the command as "app=fennec-2.3" This will only work for as high as Firefox 48.0. The support for Android 2.3x will be dropped after v48.0.
- Multiple profiles are not available on mobile platform. You will need to clear the saved data from Settings>Applications>Nightly application in order to simulate a new profile.

1. Latest good build and the first bad build where issue appeared.
2. You will need to either install both the builds (one at the time) or extract them. The most convenient is to extract both the zipped builds.
3. Search in installation folder/build folder for the "application.ini" file (Mac OS path is /Applications/Firefox.app/Contents/MacOS/application.ini).
4. Open the ".ini" files with a text editor and search for the "SourceStamp" values.
5. After doing this you will have to use the " http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=good_build_stamp&tochange=bad_build_stamp " link and replace the <good_build_stamp> and <bad_build_stamp> strings with the one obtained from the .ini files.

You should verify the link obtained, and if it works and it is related with the period when the issue appeared, you should add it to the comment for the bug where regression was performed. If you have enough experience you could also point in the comment the exact push from the pushlog page that affected the build, and CC the developer that did it (if it's still available) in order to obtain the information faster. For the moment Ryan was doing this for the pushlog links I provided but we can experience this too in the future.

In order to find the build release notes you can easily search on google for "Firefox release notes" and open the "https://www.mozilla.org/en-US/firefox/releases/" page. In this page you can view all the release notes from version 0.1 to the latest release (42.0 in the moment of writing). In my case I chose "40.0" version (https://www.mozilla.org/en-US/firefox/40.0/releasenotes/). After choosing the build, you are redirected to a page where all the major changes that entered in this build are mentioned. By looking trough the changes I observed that there were 2 changes on "html5" technology and one of them was related to "Audio Buffer". In my case the change also had a link that pointed to a page with detailed explanations and code chunks to better explain the change. This seamed that could be related a lot with the reporter problem. In my bug reply comment I mentioned the exact link of the change and asked him or his development team to look into it, since it may be the source of his problem and report any findings.

This quick search could reduce a lot the time we invest in trying to set up the environment and reproduce the issue. This procedure was reported to be one of the most used in the Firefox Desktop Validation team when triaging a bug that appeared from a version to another.

This is a change that was made for version 43.

https://www.mozilla.org/en-US/firefox/43.0beta/system-requirements/

https://www.mozilla.org/en-US/firefox/42.0/system-requirements/

1. Confirm the bug.
2. If it's the case: set the right component.
3. In Bugzilla, edit the tracking flags area: set as affected or unaffected the status-firefox fields for all Firefox versions (official Release, latest Beta, latest Aurora and latest Nightly).
4. Knowing the patch that fixed the issue is an asset in getting the fix on the affected Firefox version (the MozRegression tool is very helpful - ask the reporter or do it yourself).

Here are the steps you need to follow to install and use the tool under Mac OS:

1. First you will need to navigate to https://developer.apple.com/downloads/ and if you don't have an apple ID, you should create one.
2. After you manage to Sign In, a list with available downloads for Apple Developers is displayed. You need to chose the most recent "Hardware IO Tools for Xcode" package (you don't need Xcode installed to use this tools). Expand the package from "+" sign on the left and click the link from right side with ".dmg" format.
3. After the package is downloaded, mount it from downloads. A folder will be opened after containing the tools from the package. You will need to double click the "Network Link Conditioner.prefPane" file and choose to install it when prompted. The tool will be installed and added to "System Preferences" panel and you can always start it from there, each time when you need it.
4. The Tool comes with a couple of predefined profiles, but I suggest you to create a new one. You can do this by tapping the "manage Profiles" button. If grayed out, you need to unlock the edit possibility by clicking the "Lock" icon from bottom left and enter the user and password.
5. A new window will pop up where you can click the "+" button from bottom left to add a new profile (any name you desire).
6. After you have a new profile created, you will need to enter the desired values in "Downlink Bandwidth" for download speed and in "Uplink Bandwidth" for upload speed. Please take into consideration that the speed there is represented by default in "Kbps" which means that if you want to simulate a real 100KBps download speed, you will need to multiply the value with 8 to have the value in "kbps" (800kbps).
7. After the values are introduced, press the "OK" button to close the profiles management window and switch the tool to "ON" in order to initialize the bandwidth limitation.

Please REMEMBER that in order to return to the normal internet bandwidth speed, you will always need to switch the Tool to "OFF" after testing, otherwise the limitation will remain always ON.

Here are the steps you need to follow to install and use the tool under Windows:

1. First you will need to to navigate to https://netbalancer.com/download page and download the latest version of the NetBalancer software. The unregistered version is limited to a maximum of 3 process priorities/limits and 3 rules at a time.
2. Install the software and restart the computer after.
3. After restarting, start the program and you will observe a list with all processes under windows.
4. Right click the desired process (eg: firefox) and chose to "Limit" it. A window will be displayed where you can add the desired bandwidth value for download. You can also select the value for upload by choosing "Limit" value from the drop-down related to upload.
5. Confirm the settings and you are all done. In order to properly limit the process you desire, be sure you choose the one that consumes bandwidth while navigating trough websites / listening to videos in the browser.

Please REMEMBER that in order to return to the normal internet bandwidth speed, you will always need to reset all the limitations from the "refresh" like button from the software toolbar after testing, otherwise the limitation will remain always ON.

- Don’t use the ‘Reporter’ expression inside bugs when you’re addressing him/her. Instead, try using his/her name or Bugzilla username. (applicable for reporters with an intelligible name/email address) The desire here is to make the communication more personal. You can still use ‘reporter’ word inside comments when you’re not directly addressing him.

- If a certain developer has started working on an untriaged bug (has relevant comments inside it, changed bug’s status…) and we’re not very sure to what component to assign this bug to, first expected action would be to ask directly the developer for it (either he tells you the component or set it himself). Just in case you’re not receiving any reply from the developer, it’s ok to bring this bug into Ryan’s attention.

- For old bugs (ex: 3.2k list ones) – if the bug still reproduces and we consider it a high impact – it is ok to set comments for it. If the bug still reproduces but is lower severity, we should not add new comments to it (just change the status if case requires it). This change has come as a complain from several developers that they’re getting spammed with bug triage work for not so relevant bugs. If the low severity reproducible bug has by any chance Priority P1, we should decrease it. Applicable only if P1 has been set by the reporter. (if it has been set by dev or somebody else from Mozilla, please leave it as is) If the bug is a web compatibility one and we’re not being able to reproduce it on Chrome, then it’s ok to set a comment for it (even though it might have a lower severity).

- take enough time to try to reproduce the bug and only when we could not reproduce it or don’t have enough info to reproduce it, then ask the reporter to try other cases. We should explain the reporter what we have tried, on what version of Firefox we tried to reproduce and then ask for more information if we cannot reproduce the bug (or ask him to try to reproduce the bug in safe mode or with clean profile).

- Make sure to set the release status flags appropriately, and nominate release tracking flags if there's any uncertainty about whether the bug should block.