Ok thanks! That obstacle is now out of the way. There is a program called fribidi that is required (another question is regarding its use; it seems to relate more to language support when I read about it - languages that I am not interested in - but I guess I cannot be without it?). I downloaded the source from
https://github.com/fribidi/fribidi and built with meson, but not executable seem to be created and meson build in GtkSourceView can still not find fribidi:
$ meson build -Ddocs=false
The Meson build system
Version: 0.51.1
Source dir: /home/joachim/gtksourceview/git/fribidi
Build dir: /home/joachim/gtksourceview/git/fribidi/build
Build type: native build
Project name: fribidi
Project version: 1.0.5
C compiler for the build machine: cc (gcc 7.4.0 "cc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0")
C compiler for the host machine: cc (gcc 7.4.0 "cc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0")
Build machine cpu family: x86_64
Build machine cpu: x86_64
Compiler for C supports arguments -ansi: YES
Compiler for C supports arguments -fvisibility=hidden: YES
Checking for function "memmove" : YES
Checking for function "memset" : YES
Checking for function "strdup" : YES
Has header "stdlib.h" : YES
Has header "string.h" : YES
Has header "memory.h" : YES
Has header "strings.h" : YES
Has header "sys/times.h" : YES
Has header "strings.h" : YES (cached)
Configuring config.h using configuration
Has header "stdlib.h" : YES (cached)
Has header "string.h" : YES (cached)
Has header "strings.h" : YES (cached)
Checking for size of "int" : 4
Configuring fribidi-config.h using configuration
Program test-runner.py found: YES (/home/joachim/gtksourceview/git/fribidi/test/test-runner.py)
Build targets in project: 21
Found ninja-1.8.2 at /usr/bin/ninja
$ ll ~/gtksourceview/git/fribidi/build
totalt 108
drwxr-xr-x 10 joachim joachim 4096 jul 23 15:45 ./
drwxr-xr-x 11 joachim joachim 4096 jul 23 15:43 ../
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:43 bin/
-rw-r--r-- 1 joachim joachim 36288 jul 23 15:45 build.ninja
-rw-r--r-- 1 joachim joachim 27875 jul 23 15:45 compile_commands.json
-rw-r--r-- 1 joachim joachim 395 jul 23 15:43 config.h
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:43 doc/
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:43 gen.tab/
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:45 lib/
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:45 meson-info/
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:43 meson-logs/
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:45 meson-private/
drwxr-xr-x 3 joachim joachim 4096 jul 23 15:43 test/
$ ll ~/gtksourceview/git/fribidi/build/bin/
totalt 8
drwxr-xr-x 2 joachim joachim 4096 jul 23 15:43 ./
drwxr-xr-x 10 joachim joachim 4096 jul 23 15:45 ../
$ meson build
The Meson build system
Version: 0.51.1
Source dir: /home/joachim/gtksourceview/git/gtksourceview
Build dir: /home/joachim/gtksourceview/git/gtksourceview/build
Build type: native build
Project name: gtksourceview
Project version: 4.3.2
C compiler for the build machine: cc (gcc 7.4.0 "cc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0")
C compiler for the host machine: cc (gcc 7.4.0 "cc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0")
Build machine cpu family: x86_64
Build machine cpu: x86_64
Library m found: YES
Found pkg-config: /usr/bin/pkg-config (0.29.1)
Run-time dependency glib-2.0 found: YES 2.56.4
Run-time dependency gobject-2.0 found: YES 2.56.4
Run-time dependency gio-2.0 found: YES 2.56.4
Run-time dependency gtk+-3.0 found: YES 3.22.30
Run-time dependency libxml-2.0 found: YES 2.9.4
Found CMake: /usr/bin/cmake (3.10.2)
Run-time dependency fribidi found: NO (tried pkgconfig and cmake)
meson.build:81:0: ERROR: Dependency "fribidi" not found, tried pkgconfig and cmake
A full log can be found at /home/joachim/gtksourceview/git/gtksourceview/build/meson-logs/meson-log.txt
