build error on Manjaro 18.0.2

[amitbha]

../src/mconnect/device-proxy.vala:71.5-71.23: error: Property DeviceDBusProxy.allowed' with custom get' accessor and/or set' mutator cannot have default' value
public bool allowed {
^^^^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:79.5-79.25: error: Property DeviceDBusProxy.is_active' with custom get' accessor and/or set' mutator cannot have default' value
public bool is_active {
^^^^^^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:63.5-63.25: error: Property DeviceDBusProxy.is_paired' with custom get' accessor and/or set' mutator cannot have default' value
public bool is_paired {
^^^^^^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:27.5-27.20: error: Property DeviceDBusProxy.id' with custom get' accessor and/or set' mutator cannot have default' value
public string id {
^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:35.5-35.22: error: Property DeviceDBusProxy.name' with custom get' accessor and/or set' mutator cannot have default' value
public string name {
^^^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:43.5-43.29: error: Property DeviceDBusProxy.device_type' with custom get' accessor and/or set' mutator cannot have default' value
public string device_type {
^^^^^^^^^^^^^^^^^^^^^^^^^
../src/mconnect/device-proxy.vala:51.5-51.32: error: Property DeviceDBusProxy.protocol_version' with custom get' accessor and/or set' mutator cannot have default' value
public uint protocol_version {
......
Compilation failed: 7 error(s), 30 warning(s)
[12/57] Compiling C object 'test-mconn-crypt@exe/meson-generated_src_crypt_certificate.c.o'.
ninja: build stopped: subcommand failed.

[dmaglio]

same issue in Fedora30

[bboozzoo]

Should be fixed in master now. Please reopen if it doesn't work for you.