Bitbake Add Third Party GitHub Repo - yocto

Question

I am attempting to add a new layer to my bitbake build. There is a GitHub repo that provides code that can read a CAN frame and parse it using a DBC file. I am having trouble getting bitbake to approve of this. The repo is here and it relies on three submodules.
My bb file so far contains:
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
SRCREV_FORMAT = "linux"
SRC_URI = "git://github.com/xR3b0rn/dbcppp.git;protocol=https;branch=master \
gitsm://github.com/jarro2783/cxxopts.git;protocol=https;branch=master \
gitsm://github.com/GNOME/libxml2.git;protocol=https;branch=master \
gitsm://github.com/xR3b0rn/libxmlmm.git;protocol=https;branch=master \
"
PV = "1.0+git${SRCPV}"
SRCREV = "${AUTOREV}"
S = "${WORKDIR}/git"
When adding the third gitsm line gitsm://github.com/xR3b0rn/libxmlmm.git;protocol=https;branch=master \ I start getting errors.
ERROR: dbcppp-1.0+gitAUTOINC+linux-r0 do_configure: oe_runmake failed
ERROR: dbcppp-1.0+gitAUTOINC+linux-r0 do_configure: Execution of '/home/michael/Documents/MAIN_Application/build-fb/tmp/work/cortexa7t2hf-neon-poky-linux-gnueabi/dbcppp/1.0+gitAUTOINC+linux-r0/temp/run.do_configure.39779' failed with exit code 1
ERROR: Logfile of failure stored in: /home/michael/Documents/MAIN_Application/build-fb/tmp/work/cortexa7t2hf-neon-poky-linux-gnueabi/dbcppp/1.0+gitAUTOINC+linux-r0/temp/log.do_configure.39779
Log data follows:
| DEBUG: Executing python function extend_recipe_sysroot
| NOTE: Direct dependencies are ['/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-devtools/gcc/gcc-runtime_10.2.bb:do_populate_sysroot', 'virtual:native:/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-devtools/pseudo/pseudo_git.bb:do_populate_sysroot', '/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-devtools/quilt/quilt-native_0.66.bb:do_populate_sysroot', '/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-devtools/gcc/gcc-cross_10.2.bb:do_populate_sysroot', 'virtual:native:/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-devtools/patch/patch_2.7.6.bb:do_populate_sysroot', '/home/michael/Documents/MAIN_Application/sources/poky/meta/recipes-core/glibc/glibc_2.33.bb:do_populate_sysroot']
| NOTE: Installed into sysroot: []
| NOTE: Skipping as already exists in sysroot: ['gcc-runtime', 'pseudo-native', 'quilt-native', 'gcc-cross-arm', 'patch-native', 'glibc', 'linux-libc-headers', 'libgcc', 'xz-native', 'libmpc-native', 'autoconf-native', 'automake-native', 'mpfr-native', 'binutils-cross-arm', 'zlib-native', 'gmp-native', 'libtool-native', 'flex-native', 'texinfo-dummy-native', 'gnu-config-native', 'attr-native', 'gettext-minimal-native', 'm4-native']
| DEBUG: Python function extend_recipe_sysroot finished
| DEBUG: Executing shell function do_configure
| NOTE: make clean
| Makefile:4: *** config.mk not built. Run configure script.. Stop.
| ERROR: oe_runmake failed
| WARNING: exit code 1 from a shell command.
| ERROR: Execution of '/home/michael/Documents/MAIN_Application/build-fb/tmp/work/cortexa7t2hf-neon-poky-linux-gnueabi/dbcppp/1.0+gitAUTOINC+linux-r0/temp/run.do_configure.39779' failed with exit code 1
ERROR: Task (/home/michael/Documents/MAIN_Application/MAIN_layers/meta-MAINapplication/recipes-core/dbcppp/dbcppp_0.0.bb:do_configure) failed with exit code '1'
This is an oe_runmake error. This confuses me as I have not attempted to add a do_install or do_install_append step.
Note that my goal is to build this code and include it as a library for my application to use.
Edit 1: I updated the bb file (below). The resulting error leads to me to believe that I have to build this, set some rules for oe_runmake to follow.
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
SRCREV_FORMAT = "xR3b0rn"
SRC_URI = "git://github.com/xR3b0rn/dbcppp.git;protocol=https;branch=master \
gitsm://github.com/jarro2783/cxxopts.git;protocol=https;branch=master \
gitsm://github.com/GNOME/libxml2.git;protocol=https;branch=master \
gitsm://github.com/xR3b0rn/libxmlmm.git;protocol=https;branch=master \
"
PV = "0.0+gitr${SRCPV}"
SRCREV = "${AUTOREV}"
SRCREV_xR3b0rn = "${AUTOREV}"
S = "${WORKDIR}/git"
Edit 2: Using the solution from ensc I am able to build, but I get an odd error.
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-src went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-dbg went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-staticdev went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-dev went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-doc went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp-locale went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]
ERROR: dbcppp-1.0+gitAUTOINC+917c925638-r0 do_packagedata: QA Issue: Package version for package dbcppp went backwards which would break package feeds (from 0:1.0+git0+linux-r0 to 0:1.0+git0+917c925638-r0) [version-going-backwards]

Answer 1

write directly
SRC_URI = "gitsm://github.com/xR3b0rn/dbcppp.git;protocol=https;branch=master"
The gitsm fetcher is for downloading repositories with submodules but not for downloading the submodules itself.

Answer 2

As ensc said, gitsm will download submodules too.
Regarding Edit 2, Package version for package dbcppp-src went backwards means that you downgraded package version (you have already built higher version of package then you are trying to build currently).
You should do cleansstate of your package and rerun the build to solve it.
bitbake dbcppp -c cleansstate