Installation hangs on 'Configuring toolingorg.eclipse.equinox.launcher.*'

The installer spends several minutes in this state:

Just for comparison

• AM1 installation takes total of about 2 minutes 15 seconds
• AM2 takes 5 minutes 40 seconds

There is no shortage of memory or disk I/O availability, the CPU is not topped off (even though AM2 eats up more CPU itself during this time).

DTRACE=true reveals nothing interesting really, this is what it says in the particular moment (notice how much time the operation takes):

Configuring toolingorg.eclipse.equinox.launcher.gtk.linux.x86_64
Preparing to commit the provisioning operation.
Committing the provisioning operation. 
Operation completed in 289855 ms.