pinentry-mac @ 0.9.4 does not build on macOS Mojave 10.14

[ylluminarious (George Plymale II)]

pinentry-mac fails to install on the macOS Mojave 10.14 beta. Obviously, this is most likely to affect users who try to install gnupg2. NB: gnupg2 fails to install on Mojave as a result of this.

Here is the short error message:

--->  Fetching archive for pinentry-mac
--->  Attempting to fetch pinentry-mac-0.9.4_0.darwin_18.x86_64.tbz2 from https://packages.macports.org/pinentry-mac
--->  Attempting to fetch pinentry-mac-0.9.4_0.darwin_18.x86_64.tbz2 from http://ywg.ca.packages.macports.org/mirror/macports/packages/pinentry-mac
--->  Attempting to fetch pinentry-mac-0.9.4_0.darwin_18.x86_64.tbz2 from http://nue.de.packages.macports.org/pinentry-mac
--->  Fetching distfiles for pinentry-mac
--->  Attempting to fetch pinentry-mac-0.9.4.tar.gz from https://distfiles.macports.org/pinentry-mac
--->  Verifying checksums for pinentry-mac
--->  Extracting pinentry-mac
--->  Configuring pinentry-mac
--->  Building pinentry-mac
Error: Failed to build pinentry-mac: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_aqua_pinentry-mac/pinentry-mac/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port gnupg2 failed

I am attaching the log file as well. The specific OS version is:

ProductName:	Mac OS X
ProductVersion:	10.14
BuildVersion:	18A377a

Also, I am using Xcode 10 beta 6 although Xcode 9.4.1 is installed as well. More info on my current setup is available at #57080.

[Ionic (Mihai Moldovan)]

Duplicate of #57178 (really the other way around, but since pmetzger already made changes...)