Error during make: (Ada 2005) non-graphic character not permitted in string literal

I've cloned the startup-gen repo as well as downloaded the Release version 21.0.0 of templates-parser and each result in the following error when running make:

System info:
OS: Ubuntu 18.04.5 x86_64
GNat Studio version:
GNAT Studio Community 2020 (20200427) hosted on x86_64-pc-linux-gnu
GNAT Community 2020 (20200429-93) targetting arm-eabi
SPARK Community 2020 (20200429)
Active toolchain: arm-eabi

=== Make ERROR ====
~/templates-parser$ make
Setup
[mkdir] object directory for project Templates_Parser
[mkdir] library directory for project Templates_Parser
Compile
[Ada] templates_parser-xml.adb
[Ada] templates_parser-utils.adb
[Ada] templates_parser-debug.adb
[Ada] templates_parser.adb
[Ada] templates_parser-query.adb
[Ada] templates_parser-input__standalone.adb
[Ada] templates_parser_tasking__standard_tasking.adb
[Ada] templates_parser-configuration__standalone.ads
Build Libraries
[gprlib] templates_parser.lexch
[archive] libtemplates_parser.a
[index] libtemplates_parser.a
Setup
[mkdir] object directory for project Templates_Parser
[mkdir] library directory for project Templates_Parser
Compile
[Ada] templates_parser-xml.adb
[Ada] templates_parser-utils.adb
[Ada] templates_parser-debug.adb
[Ada] templates_parser.adb
[Ada] templates_parser-query.adb
[Ada] templates_parser-input__standalone.adb
[Ada] templates_parser_tasking__standard_tasking.adb
[Ada] templates_parser-configuration__standalone.ads
Build Libraries
[gprlib] templates_parser.lexch
[link library] libtemplates_parser.so
Setup
[mkdir] object directory for project Tools
[mkdir] exec directory for project Tools
Compile
[Ada] templates2ada.adb
[Ada] templatespp.adb
Bind
[gprbind] templates2ada.bexch
[Ada] templates2ada.ali
[gprbind] templatespp.bexch
[Ada] templatespp.ali
b__templatespp.adb:71:09: (Ada 2005) non-graphic character not permitted in string literal
gprbind: compilation of binder generated file failed
b__templates2ada.adb:71:09: (Ada 2005) non-graphic character not permitted in string literal
gprbind: compilation of binder generated file failed
binding of templatespp.adb failed
binding of templates2ada.adb failed
gprbuild: *** post compilation phase failed
Makefile:114: recipe for target 'build' failed
make: *** [build] Error 4

Start by reproducing the failure with make and inspect Makefile:114, then examine the generated b__templatespp.adb and b__templates2ada.adb files at line 71. Compare the binder output with the reported non-graphic character error and confirm a successful build as the completion criterion.