Author: Mathias Lipowski

Sourcetree keeps asking for password

When Sourcetree keeps asking for password when committing or pushing data to a server, the following solution worked for me:

Go to terminal in your project folder and enter:

git config credential.helper store
git pull

Input your username and password and press enter. That’s it.

Source (somewhere in between the lines):

PNG – deactivate interlace to avoid ‘libpng warning: Interlace handling should be turned on when using png_read_image’

I stumbled appon a warning message that was thrown by PHP when handling images with GD lib (e.g. imagecreatefrompng()). The message shown was:

libpng warning: Interlace handling should be turned on when using png_read_image

This message even exists, when deactivating ‘interlace’ with the help of:

imageinterlace($img, false);

The only solution is to deactivate for the processed image(s). This is possible with ImageMagick. To deactivate interlace on all images of a folder, the following command can be used:

magick mogrify -interlace none *.png

I used ImageMagick on macos and installed it with with HomeBrew:

brew install imagemagick

Composer – PHP Fatal error: Allowed memory size of ## bytes exhausted

Composer may sometimes fail on some commands with this message:

PHP Fatal error: Allowed memory size of ## bytes exhausted <...

In this case, the PHP memory_limit should be increased.

Note: Composer internally increases the memory_limit to 1.5G.

To get the current memory_limit value, run:

php -r "echo ini_get('memory_limit').PHP_EOL;"

Try increasing the limit in your php.ini file (ex. /etc/php5/cli/php.ini for Debian-like systems):

; Use -1 for unlimited or define an explicit value like 2G
memory_limit = -1

Composer also respects a memory limit defined by the COMPOSER_MEMORY_LIMIT environment variable:

COMPOSER_MEMORY_LIMIT=-1 composer.phar <...>

Or, you can increase the limit with a command-line argument:

php -d memory_limit=-1 composer.phar <...>

This issue can also happen on cPanel instances, when the shell fork bomb protection is activated. For more information, see the documentation of the fork bomb feature on the cPanel site.


Xcode fails to generate source files from intent definition files when using the Legacy Build System

The workaround for this problem is the following: First, add a Run Script phase before the Compile Sources phase of your target:

xcrun intentbuilderc generate -input ${SRCROOT}/PATH/TO/Intents.intentdefinition -output ${SRCROOT}/Intents -classPrefix "" -language Swift -swiftVersion 5.0

Then, add all of the generated files from the output path specified in the command above to all required targets in your project.


Change default reading font in Outlook from Times New Roman to Calibri (or any other)

I use Outlook 2016 and some emails are shown in Times New Roman, even if the default font was set to Calibri. This is the case, when HTML mails do not have any CSS style. In this case, Outlook uses the default fall back font Times New Roman. It took me some time to realise that there is no setting for this in Outlook.

But: the related setting can be found in Word 2016 (yes, Word!).

To change the setting, open Word and go to:

File > Options > Advanced > General section > Web Options… > Fonts tab > Proportional font …

There you can change the setting with Times New Roman font to any other font. After the change you have to restart Outlook. Each unformated HTML mail should now be displayed in the selected font.

Photo by Federica Galli on Unsplash.

Background tasks in iOS

As already discussed in Background task in iOS action extension, it sometimes becomes necessary to perform time consuming tasks in the background. This is really important, if such a task would block the user interaction. Especially for action and share extensions, this might lead to some waiting time before a task completes and the extension disappears. After several attempts to realise a working solution, the following code help to extends an App’s background execution time.

This code was described in the article Extending Your App’s Background Execution Time.

Extending the background execution time in an app

func performTask()
   // Perform the task on a background queue. {
      // Request the task assertion and save the ID.
      self.backgroundTaskID = UIApplication.shared.
                 beginBackgroundTask (withName: "Perform Long Task") {
         // End the task if time expires.
         self.backgroundTaskID = UIBackgroundTaskInvalid
      // Run task synchronously.
      // End the task assertion.
      self.backgroundTaskID = UIBackgroundTaskInvalid

Extending the background execution time in an extension

func performTask()
   // Perform the task in background.
   let processinfo = ProcessInfo()
   processinfo.performExpiringActivity(withReason: "Long task") { (expired) in
      if (!expired) {
         // Run task synchronously.
      else {
         // Cancel task.

As mentioned in the documentation, the ProcessInfo code block is called a second time if the system need to suspend the process:

If your block is still executing and the system need to suspend the process, the system executes your block a second time with the expired parameter set to true. Your block must be prepared to handle this case. When the expired parameter is true, stop any in-progress tasks as quickly as possible.


Important: it’s important that the tasks are executed synchronously. When the end of the block is reached, the thread will terminate and end the execution of your task. If your tasks are asynchron, you can use a loop like shown below to wait inside the background thread until the asynchron task is finished:

// Keep background thread alive until asynchron task ends.
repeat {
} while(taskIsRunning)

General thoughts on using background tasks in iOS

A good summary of background tasks is available at

Photo by Jonathan Borba on Unsplash.

Note To Self: how to instantly create tasks in Trello

If you are using the mail import feature of Trello, you can speed up the notes with Note To Self Mail. The app creates notes in Trello in seconds.

Setup Note To Self Mail for Trello

1. Get your Trello email address

Get your Trello email address by open up one of your boards in Trello and go to “Email-to-board Settings” ind the settings section of the sidebar. Emails sent to this address will appear as a task in this board. The subject of the email will become the title and the body will become the description.

2. Add your Trello email address to Note To Self Mail

Add this email address to Note To Self Mail. You can also set the label to “Trello” or any other descriptive name.

Note To Self Mail > Settings > Add email …

3. Adjust the subject

Trello uses the subject as a main source of a new note. Set the subject to “Use first line of note”. This ensures, that the first line is used as subject and all the other text lines are moved to the description of the task.

Note To Self Mail > Settings > Add email … > Subject


There are some shortcuts or special chars that can be used in the subject of the mail. All available features are described in Trello’s documentation: Formatting Tips (opens in a new tab)”>Creating cards by email > Formatting Tips.

Now, you can send any note to Trello. With the following text …

… a new task will be created in Trello …

You might notice, that the task was placed in the correct list (as set in Trello) and was tagged with “home”. All the other contents of the input (line 2 up to the end) are moved to the task description. That’s it!