I wanted to build firmware according to the getting started guide (http://www.8devices.com/wiki/carambola:2:gettingstarted)
But building it fails all the time.
I am using Ubuntu 18.04.1 LTS on a virtual machine (Virtual box from oracle)

Error output after entering the command "make -j1 V=s":

(cd /home/administrator/carambola2/build_dir/host/automake-1.15; AUTOM4TE=/home/administrator/carambola2/staging_dir/host/bin/autom4te AUTOCONF=/home/administrator/carambola2/staging_dir/host/bin/autoconf AUTOMAKE=/home/administrator/carambola2/staging_dir/host/bin/automake ACLOCAL=/home/administrator/carambola2/staging_dir/host/bin/aclocal AUTOHEADER=/home/administrator/carambola2/staging_dir/host/bin/autoheader LIBTOOLIZE=/home/administrator/carambola2/staging_dir/host/bin/libtoolize LIBTOOL=/home/administrator/carambola2/staging_dir/host/bin/libtool M4=/home/administrator/carambola2/staging_dir/host/bin/m4 AUTOPOINT=true STAGING_DIR="" ./bootstrap.sh)
Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/\${ <-- HERE ([^ \t=:+{}]+)}/ at ./bin/automake.tmp line 3938.
Makefile:50: recipe for target '/home/administrator/carambola2/build_dir/host/automake-1.15/.configured' failed
make[3]: *** [/home/administrator/carambola2/build_dir/host/automake-1.15/.configured] Error 255
make[3]: Leaving directory '/home/administrator/carambola2/tools/automake'
tools/Makefile:134: recipe for target 'tools/automake/compile' failed
make[2]: *** [tools/automake/compile] Error 2
make[2]: Leaving directory '/home/administrator/carambola2'
tools/Makefile:133: recipe for target '/home/administrator/carambola2/staging_dir/target-mips_34kc_musl-1.1.14/stamp/.tools_install_yyyyyynynynyyyyyyynyyyyyyyyyyyyynyyyyynnyynynyyyynnnyy' failed
make[1]: *** [/home/administrator/carambola2/staging_dir/target-mips_34kc_musl-1.1.14/stamp/.tools_install_yyyyyynynynyyyyyyynyyyyyyyyyyyyynyyyyynnyynynyyyynnnyy] Error 2
make[1]: Leaving directory '/home/administrator/carambola2'
/home/administrator/carambola2/include/toplevel.mk:192: recipe for target 'world' failed
make: *** [world] Error 2

Do you have any suggestions on how to solve this problem?

Found the Solution to this Problem in another post in this community

You have to take the text from
https://git.openwrt.org/?p=openwrt/open ... 2745aeaf77

Save it in a file named: 010-automake-port-to-Perl-5.22-and-later.patch

Place it in tools/automake/patches

In this folder should already be three other patch files. Seems like they forgot to put the last one in it.
Here the source of the patch file : https://git.openwrt.org/?p=openwrt/open ... 2745aeaf77