I've been trying to build gnome-todo to get involved coding for gnome. 

I've follow the newcomers build guide: https://wiki.gnome.org/Newcomers/BuildProject 

and, when trying to build gnome-todo from builder (using flatpak) I got this message:

configure: error: Package requirements (gmodule-export-2.0
                  gio-2.0 >= 2.43.4
                  glib-2.0 >= 2.43.4
                  goa-1.0 >= 3.2.0
                  gtk+-3.0 >= 3.22.0
                  libecal-1.2 >= 3.13.90
                  libedataserver-1.2 >= 3.17.1
                  libedataserverui-1.2 >= 3.17.1
                  libical >= 0.43
                  libpeas-1.0 >= 1.17
                  rest-0.7
                  json-glib-1.0) were not met:
No package 'rest-0.7' found
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.
Alternatively, you may set the environment variables GNOME_TODO_CFLAGS
and GNOME_TODO_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.


I asked on the newcomers IRC chat and some people answered that they had the same problem so it would be a build problem and they'll try to solve it. I had installed rest-devel package and, as I'm using fedora 26, I have the 0.8 version. One person told me that seems like builder is looking for the exactly 0.7 version but, when he tried changing configure.ac, it had no effect.

They suggested me to build it from source using jhbuild and try to solve it myself while they do so I tried and, after set up jhbuild propertly I got:

*** Building gcab *** [10/52]
make -j 9 
  CC       libgcab/libgcab_1_0_la-gcab-folder.lo
/home/grg121/jhbuild/checkout/gcab/libgcab/gcab-folder.c: In function ‘gcab_folder_class_init’:
/home/grg121/jhbuild/checkout/gcab/libgcab/gcab-folder.c:114:28: error: ‘GCAB_TYPE_COMPRESSION’ undeclared (first use in this function); did you mean ‘PROP_COMPRESSION’?
                            GCAB_TYPE_COMPRESSION, 0,
                            ^~~~~~~~~~~~~~~~~~~~~
                            PROP_COMPRESSION
/home/grg121/jhbuild/checkout/gcab/libgcab/gcab-folder.c:114:28: note: each undeclared identifier is reported only once for each function it appears in
make: *** [Makefile:873: libgcab/libgcab_1_0_la-gcab-folder.lo] Error 1
*** Error during phase build of gcab: ########## Error running make -j 9  *** [10/52]

So I got stagnant again...

I write this here so somebody maybe could know how to fix it or could conduct me to find a solution. 

I would like to help but I'm not sure what to do...

regards!