Pamac cannot be build with vala-0.56.6: "error: The type name `GLib.EqualFuncFull' could not be found"

Distribution

Archlinux

Desktop environment

GNOME

When I try to build pamac-aur with vala 0.56.6 I got this error message:

[7/53] Compiling Vala source ../src/ve...c/transaction-cli.vala ../src/cli.vala
FAILED: src/pamac.p/version.c src/pamac.p/transaction-cli.c src/pamac.p/cli.c 
valac -C --pkg pamac --pkg gio-2.0 --color=always --directory src/pamac.p --basedir ../src --pkg=posix --target-glib=2.38 --vapidir=/home/fred/pamac-aur-git/src/pamac/vapi --pkg=linux ../src/version.vala ../src/transaction-cli.vala ../src/cli.vala
gio-2.0.vapi:1769.96-1769.113: error: The type name `GLib.EqualFuncFull' could not be found