How does lightdm determine which sessions to show as options?

[jejones3141]

I switched to a ppa to get an up-to-date and complete E17 including some packages to let removable devices be detected and automounted--and after doing that, I no longer see enlightenment as a possible choice of session.

UPDATE: It helps to install all the pertinent packages.

Here's what I've determined so far:


/usr/share/xsessions contains a file named enlightenment.desktop, which, as far as I can tell, looks reasonable.
/var/lightdm/x-0-greeter.log contains a line saying it's ignoring the enlightenment.desktop file.

So... what is it that determines whether a particular session is shown as a choice under lightdm? There are other files that are ignored. I could see ignoring the guest sessions when I, a non-guest, log in (BTW, if one wants to give a guest other window manager options, how is that done?), and gnome.desktop is ignored (its Name= value is the same as another file, ubuntu.desktop, but if that is the reason it's ignored, why does gnome.desktop appear first in the log file?) AfterStep.desktop is ignored as well, so I will look for commonalities between it and enlightenment.desktop, but I'd appreciate any pointer to info on what determines whether a given session is listed or not.

[jejones3141]

More info: I notice that some of the .desktop files contain either

NoDisplay=true

or

Hidden=true

I'll see whether getting rid of NoDisplay=true makes the AfterStep option appear, but enlightenment.desktop contains neither of those. Its contents follow:

[Desktop Entry]
Encoding=UTF-8
Name=Enlightenment
Name[ru]=Enlightenment
Name[el]=Enlightenment
Name[eo]=Enlightenment
Name[tr]=Enlightenment
Comment=Log in using Enlightenment (Version 0.16.999.0)
Comment[ru]=Войти используя Enlightenment (Версия 0.16.999.0)
Comment[el]=Είσοδος με το Enlightenment (Έκδοση 0.16.999.0)
Comment[eo]=Ensaluti pere de Enlightenment (Versio 0.16.999.0)
Comment[fr]=Ouvrir une session Enlightenment (Version 0.16.999.0)
Comment[it]=Accedi con Enlightenment (Versione 0.16.999.0)
Comment[pt]=Inicie a sessão com o Enlightenment (Versão 0.16.999.0)
Comment[tr]=Enlightenment kullanarak giriş yaın (Version 0.16.999.0)
Comment[ko]=Enlightenment 로그인(버전 0.16.999.0)
Type=XSession
Icon=/usr/share/enlightenment/data/images/enlightenment.png
Exec=/usr/bin/enlightenment_start
TryExec=/usr/bin/enlightenment_start

[Krytarik]

[Desktop Entry]
Encoding=UTF-8
Name=Enlightenment
Name[ru]=Enlightenment
Name[el]=Enlightenment
Name[eo]=Enlightenment
Name[tr]=Enlightenment
Comment=Log in using Enlightenment (Version 0.16.999.0)
Comment[ru]=Войти используя Enlightenment (Версия 0.16.999.0)
Comment[el]=Είσοδος με το Enlightenment (Έκδοση 0.16.999.0)
Comment[eo]=Ensaluti pere de Enlightenment (Versio 0.16.999.0)
Comment[fr]=Ouvrir une session Enlightenment (Version 0.16.999.0)
Comment[it]=Accedi con Enlightenment (Versione 0.16.999.0)
Comment[pt]=Inicie a sessão com o Enlightenment (Versão 0.16.999.0)
Comment[tr]=Enlightenment kullanarak giriş yaın (Version 0.16.999.0)
Comment[ko]=Enlightenment 로그인(버전 0.16.999.0)
Type=XSession
Icon=/usr/share/enlightenment/data/images/enlightenment.png
Exec=/usr/bin/enlightenment_start
TryExec=/usr/bin/enlightenment_start
Apart from the "NoDisplay" and "Hidden" keys, both of which shouldn't be set to "true", according to the Desktop Entry Specification "XSession" is not a valid value for "Type", it should be "Application" instead:

http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#recognized-keys

Regards.

[jejones3141]

Apart from the "NoDisplay" and "Hidden" keys, both of which shouldn't be set to "true", according to the Desktop Entry Specification "XSession" is not a valid value for "Type", it should be "Application" instead:

http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#recognized-keys

Regards.

Thank you! It turns out that my real problem lay elsewhere; I had not installed a needed package that I can't believe I overlooked, i.e. e17 itself. In any case, I have learned more about .desktop files.