I am trying out Vala with the intent to maybe develop an applet for UB.
Everything is still at a very initial state and I am working myself though the vala tuts here.
I am using VS Code (don’t know if this is the best tool), and compiling works ok when I use GTK2 with the command
valac --pkg gtk+-2.0 gtk-hello.vala
But when use GTK3
valac --pkg gtk+-3.0 gtk-hello.vala
I am getting the error
gtk-hello.vala.c:7:10: fatal error: gtk/gtk.h: No such file or directory #include <gtk/gtk.h> #include <gtk/gtk.h>
The vala documentation on the net is scarce, and what I found to solve the issue was installing the libgtk-3-dev library, with:
sudo apt-get install libgtk3.0-dev
But that returns:
Reading state information... Done
Package libgtk-3-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source
E: Package 'libgtk-3-dev' has no installation candidate
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libgtk-3-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is
only available from another source
E: Package 'libgtk-3-dev' has no installation candidate
Listing… Done
libreoffice-style-sifr/disco-updates,disco-updates,disco-security,disco-security 1:6.2.6-0ubuntu0.19.04.1 all [upgradable from: 1:6.2.5-0ubuntu0.19.04.1]
N: There are 2 additional versions. Please use the ‘-a’ switch to see them.
rainer@rainer:~$ apt list --upgradable -a
Listing… Done
libreoffice-style-sifr/disco-updates,disco-updates,disco-security,disco-security 1:6.2.6-0ubuntu0.19.04.1 all [upgradable from: 1:6.2.5-0ubuntu0.19.04.1]
libreoffice-style-sifr/now 1:6.2.5-0ubuntu0.19.04.1 all [installed,upgradable to: 1:6.2.6-0ubuntu0.19.04.1]
libreoffice-style-sifr/disco,disco 1:6.2.2-0ubuntu2 all
*********
sudo apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
*********
sudo apt install libgtk-3-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libgtk-3-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'libgtk-3-dev' has no installation candidate