Hi,
I have a newly installed Librem 15v4. I like to change the keyboard mappings from English to German in PureOS but I can’t figure out how to adapt the key mapping to replace the “missing” “|” “Pipe” key. Am I missing something?
Any help is really appreciated. 
Which physical keyboard layout do you own?
US-ANSI?
So I think in your case it is helpful to give you some overview about different keyboard layouts.
Please find a comprehensive comparison here.
My assumtion in your case: You are trying to type on a US ANSI keyboard as if it were a German one (DE ISO). Example: You would like to press “y” resulting in “z” as output.
Of course, this works. BUT as you can find in the link above: US ANSI keyboard has one physical key less than DE ISO. The key for “<, >, |” writes 3 different characters. “<” and “>” can be found elsewhere when having changed. But “|” needs to be typed with “Alt Gr” pressed (on DE ISO) and is therefore not assigned when switching to German input on US ANSI keyboard.
You can still use “Alt + 124” to type “pipe”. Wow that rhymes. 
Or another combination that works on Linux distros like PureOS (Debian).
Thanks for your answer and your explanations. I am aware that the US-ANSI layout has this one key missing. I changed the system keyboard setting to DE ISO, thinking that the “Pipe” would just be attached to a new key combo because of the change. At some point I realized it wasn’t, so I tried to to define a key combination with Gnome Tweaks, but that doesn’t work. Same result for “key-mapper” which I found on github.
I also tried to define a key combo with xkb, but I couldn’t figure out how to intercept the correct keycodes and where to set them for Wayland.
It is not a solution to your original problem, but if your need for the german layout is covered with the german-typical latin extensions (äöüß) plus €-symbol, you might try to set your xkb layout to de(us), which adds the extensions to the corresponding basic letters on a basic us layout via AltGr-composition. In the basic layout however the compositing for the accents like á à is not available.
Thanks for this suggestion. I changed indeed the keyboard layout to an us based variant as temporary solution.
So for “ä” I would have to type AltGr + [ or so and for Ä I press AltGr + Shift + [ ?
And is the right Alt key automatically AltGr? I consider buying a L14. I like English layouts but those characters you mentioned are missing and frequent in German.
I found a solution by myself. After some digging in stackexchange posts and the comparison of different layout files in /usr/share/X11/xkb/ I adapted the file /usr/share/X11/xkb/symbols/de in the following way:
default
xkb_symbols "basic" {
include "latin(type4)"
name[Group1]="German";
//Anpassung
key.type[Group1] = "EIGHT_LEVEL";
//Anpassung Ende
key <AE02> { [ 2, quotedbl, twosuperior, oneeighth ] };
...
key <BKSL> { [numbersign, apostrophe, rightsinglequotemark, dead_breve ] };
//Anpassung
key <AB01> { [ y, Y, guillemotright, U203A, less ] };
key <AB02> { [ x, X, guillemotleft, U2039, greater ] };
key <AB03> { [ c, C, cent, copyright, bar ] };
//Anpassung Ende
key <AB04> { [ v, V, doublelowquotemark, singlelowquotemark ] };
...
include "level3(ralt_switch)"
//Anpassung
include "level5(rctrl_switch)"
//Anpassung Ende
};
The result is as desired: By pressing RCTRL+z I get a “<”, with the x key a “>” and with RCTRL and c I get my beloved “|”
No, on this layout you get “ä” by pressing “AltGr + a”, “Ö” by pressing “AltGr + Shift + O”, “ß” by pressing “AltGr + s” etc.
I am not yet using PureOS, but I am looking forward to buy a L14, I am not sure if you can choose this layout in this distribution.
In my opinion, since the US layout is most often a fallback layout when other configurations don’t work out, the advantage of having a modified US layout is that you automatically have all non-alphanumeric characters ready for typing and are also used to the layout. The thing I miss most from this layout compared to standard German layout are the ` and ’ compositions on vowels, but when I need them I am now used to switching to a secondary layout. Another plus is that the German in many cases has unpractical key combinations for special characters, and this can be avoided on the modified US layout.
There is another possibility I found out about just recently: the EURkey layout (Wikipedia). This adds to a standard US layout a broad set of letters used in several European languages. I am still looking if I can get used to it.
Please share your experience.
When I look at the L14 keyboard it seems only to have alt keys but not AltGr. Is that a problem?
I actually have no L14 in my hands, so I can’t test it.
In any case, the xkb keymap for EURkey on my installation identifies the AltGr key as “ralt”, (right Alt?), as do other keymaps; I think the visible label/imprint on the upside of the key does not stop the system from identifying this particular button as the Alt-modifier-key on the right side of the keyboard, and that you can consider the behavior of your right Alt-key as the same of an AltGr-key.
Please confirm or refute this.