Compile error on vala 0.47

Compiling Pamac 9.3.0 on Ubuntu 19.10 will error out in error: function ‘__errno_location’ is initialized like a variable.

root@discover:/opt/manjaro/tools/pamac# mkdir builddir
root@discover:/opt/manjaro/tools/pamac# cd builddir/
root@discover:/opt/manjaro/tools/pamac/builddir# meson --prefix=/usr --sysconfdir=/etc -Denable-appindicator=true -Denable-snap=true --buildtype=debug
The Meson build system
Version: 0.51.2
Source dir: /opt/manjaro/tools/pamac
Build dir: /opt/manjaro/tools/pamac/builddir
Build type: native build
Project name: pamac
Project version: 9.0
C compiler for the host machine: cc (gcc 9.2.1 "cc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008")
Vala compiler for the host machine: valac (valac 0.47.4)
Build machine cpu family: x86_64
Build machine cpu: x86_64
Found pkg-config: /usr/bin/pkg-config (0.29.1)
Found pkg-config: /usr/bin/pkg-config (0.29.1)
Run-time dependency gobject-2.0 found: YES 2.62.1
Run-time dependency gio-2.0 found: YES 2.62.1
Run-time dependency gthread-2.0 found: YES 2.62.1
Run-time dependency libalpm found: YES 12.0.1
Run-time dependency json-glib-1.0 found: YES 1.4.4
Run-time dependency libsoup-2.4 found: YES 2.68.2
Run-time dependency polkit-gobject-1 found: YES 0.105
Run-time dependency libnotify found: YES 0.7.8
Run-time dependency appstream-glib found: YES 0.7.14
Run-time dependency gtk+-3.0 found: YES 3.24.12
Run-time dependency gdk-3.0 found: YES 3.24.12
Run-time dependency gdk-pixbuf-2.0 found: YES 2.40.0
Run-time dependency vte-2.91 found: YES 0.58.2
Library posix found: YES
Library m found: YES
Run-time dependency snapd-glib found: YES 1.49
Run-time dependency gmodule-2.0 found: YES 2.62.1
Program g-ir-compiler found: YES (/usr/bin/g-ir-compiler)
Run-time dependency appindicator3-0.1 found: YES 12.10.0
Configuring org.manjaro.pamac.manager.service using configuration
Configuring org.manjaro.pamac.daemon.service using configuration
Program pacman-mirrors found: YES (/usr/local/bin/pacman-mirrors)
Build targets in project: 21
Found ninja-1.9.0 at /usr/bin/ninja
root@discover:/opt/manjaro/tools/pamac/builddir# ninja
[12/84] Compiling Vala source ../src/packag...gin_loader.vala ../src/snap_interface.vala.
../src/alpm_package.vala:147.1-147.20: warning: method `compare_name_pkg' never used
int compare_name_pkg (Pamac.Package pkg_a, Pamac.Package pkg_b) {
^^^^^^^^^^^^^^^^^^^^
../src/alpm_config.vala:354.2-354.18: warning: method `AlpmConfig.write' never used
	public void write (HashTable<string,Variant> new_conf) {
	^^^^^^^^^^^^^^^^^
../src/alpm_utils.vala:575.3-575.28: warning: method `Pamac.AlpmUtils.download_pkg' never used
		public string download_pkg (string sender, string url) {
		^^^^^^^^^^^^^^^^^^^^^^^^^^
Compilation succeeded - 3 warning(s)
[15/84] Compiling Vala source ../src/versio...gin_loader.vala ../src/snap_interface.vala.
../src/alpm_package.vala:51.3-51.26: warning: method `Pamac.AlpmPackage.dup' never used
		internal AlpmPackage dup () {
		^^^^^^^^^^^^^^^^^^^^^^^^
../src/alpm_package.vala:147.1-147.20: warning: method `compare_name_pkg' never used
int compare_name_pkg (Pamac.Package pkg_a, Pamac.Package pkg_b) {
^^^^^^^^^^^^^^^^^^^^
../src/alpm_utils.vala:781.3-781.33: warning: method `Pamac.AlpmUtils.trans_check_prepare' never used
		public bool trans_check_prepare (bool sysupgrade,
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Compilation succeeded - 3 warning(s)
[21/84] Compiling C object 'src/25a6634@@pamac@sha/meson-generated_alpm_utils.c.o'.
FAILED: src/25a6634@@pamac@sha/meson-generated_alpm_utils.c.o 
cc -Isrc/25a6634@@pamac@sha -Isrc -I../src -I/usr/include/x86_64-linux-gnu -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/json-glib-1.0 -I/usr/include/libappstream-glib -I/usr/include/uuid -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libsoup-2.4 -I/usr/include/libxml2 -fdiagnostics-color=always -pipe -w -g -fPIC -pthread '-DGETTEXT_PACKAGE="pamac"' -D_FILE_OFFSET_BITS=64 -MD -MQ 'src/25a6634@@pamac@sha/meson-generated_alpm_utils.c.o' -MF 'src/25a6634@@pamac@sha/meson-generated_alpm_utils.c.o.d' -o 'src/25a6634@@pamac@sha/meson-generated_alpm_utils.c.o' -c 'src/25a6634@@pamac@sha/alpm_utils.c'
alpm_utils.c: In function ‘pamac_alpm_utils_update_dbs’:
alpm_utils.c:2626:4: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_init’:
alpm_utils.c:3584:3: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_sysupgrade’:
alpm_utils.c:3681:3: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_add_pkg_real’:
alpm_utils.c:3858:3: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_load_pkg’:
alpm_utils.c:4835:3: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c:4905:4: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_remove_pkg’:
alpm_utils.c:5093:4: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_prepare_real’:
alpm_utils.c:5584:3: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_build_prepare’:
alpm_utils.c:7761:4: error: function ‘__errno_location’ is initialized like a variable
alpm_utils.c: In function ‘pamac_alpm_utils_trans_commit_real’:
alpm_utils.c:10337:3: error: function ‘__errno_location’ is initialized like a variable
[22/84] Compiling C object 'src/25a6634@@pamac@sha/meson-generated_database.c.o'.
ninja: build stopped: subcommand failed