How to install Meld on Ubuntu

Meld is popular cross-platform visual diff and merge tool. It can compare files and directories.

Clone Meld repository (use HTTPS URI, not the SSH-based one unless you've set up SSH key for that repo):

$ git clone https://gitlab.gnome.org/GNOME/meld.git

Check the status of master and release branches. When I built and run the app from master, I got this error:

$ meld

Meld requires GtkSourceView 4 4.0.0 or higher.

Then I found the following comment here:

> If Meld is complaining about GtkSourceView 4, you're using master, not 3.20.1.

This means I should have checked out the release branch for the desired version:

$ cd meld/
$ git checkout meld-3-20

When I was running the installer:

$ python3 setup.py install --prefix=/usr

...I was getting errors related to missing packages:

unable to execute 'intltool-update': No such file or directory
error: command 'intltool-update' failed with exit status 1

unable to execute 'xmllint': No such file or directory

error: command 'xmllint' failed with exit status 1

unable to execute 'glib-compile-resources': No such file or directory

error: command 'glib-compile-resources' failed with exit status 1

I installed the required packages (the package needed for xmllint is libxml2-utils):

$ sudo apt update

$ sudo apt upgrade

$ sudo apt install intltool 

$ sudo apt install xmllint

E: Unable to locate package xmllint

$ sudo apt install libxml2-utils

$ glib-compile-resources --help

Command 'glib-compile-resources' not found, but can be installed with:

sudo apt install libglib2.0-dev-bin

$ sudo apt install libglib2.0-dev-bin

...and run again installer:

$ python3 setup.py install --prefix=/usr

...which now complained about permissions:

creating /usr/lib/python3/dist-packages/meld

error: could not create '/usr/lib/python3/dist-packages/meld': Permission denied

Meld was finally installed with sudo user:

$ sudo python3 setup.py install --prefix=/usr

...

running install_egg_info

Writing /usr/lib/python3/dist-packages/meld-3.21.0.egg-info

When I run it first time I got this error:

$ meld

Meld requires pygobject 3.30.0 or higher.

To install the latest version of PyGObject:

$ pip3 install PyGObject 

Installing PyGObject complained couple of times about missing packages:

No package 'glib-2.0' found

Try installing it with: 'sudo apt install libglib2.0-dev'

No package 'gobject-introspection-1.0' found

Try installing it with: 'sudo apt install libgirepository1.0-dev'

No package 'cairo' found

Try installing it with: 'sudo apt install libcairo2-dev'

Installing PyGObject was successful once I installed all missing packages:

$ sudo apt install libglib2.0-dev

$ sudo apt install libgirepository1.0-dev

$ sudo apt install libcairo2-dev

$ pip3 install pycairo

I rebuilt the app and run it again:

$ sudo python3 setup.py install --prefix=/usr

$ meld

This time it opened with no issues:

References:

About Meld

Meld