Update Vagrant image to Ubuntu focal.

Vagrantfile

@@ -19,11 +19,11 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   # please see the online documentation at vagrantup.com.
 
   # Every Vagrant virtual environment requires a box to build off of.
-  config.vm.box = "ubuntu-bionic64"
+  config.vm.box = "ubuntu-focal64"
 
   config.vm.provider "virtualbox"
 
-  config.vm.box_url = "https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64-vagrant.box"
+  config.vm.box_url = "https://cloud-images.ubuntu.com/focal/20200804/focal-server-cloudimg-amd64-vagrant.box"
 
   if Vagrant::Util::Platform.windows?
 	  config.vm.network :forwarded_port, guest: 80, host: 80, host_ip: "127.0.0.1"

freeciv/README.md

@@ -11,4 +11,5 @@ apply_patches.sh - applies patches against the Freeciv C source code.
 
 version.txt - contains the Git revision of Freeciv to check out from Git.
 
-The Freeciv C server is installed to $HOME/freeciv.
+The Freeciv C server is copied to the /tmp directory, and built there, then installed to $HOME/freeciv.
+Building in /tmp is a workaround for a file permission issue on Vagrant/VirtialBox.

freeciv/prepare_freeciv.sh

@@ -25,6 +25,14 @@ if ! ./apply_patches.sh ; then
   exit 1
 fi
 
-( cd freeciv
+echo "Copying Freeciv to /tmp, and compiling Freeciv in /tmp"   
+# Copying Freeciv to /tmp, is a workaround for compiling Freeciv in a Vagrant box on VirtualBox, since in this environment
+# autogen.sh can fail with this error:   "./conftest: Permission denied", which seems to be related to executable file permissions in a VirtualBox file system.
+cp freeciv /tmp -rf
+cp freeciv-web.project /tmp
+
+( cd /tmp/freeciv
   ./autogen.sh CFLAGS="-O3" --enable-mapimg=magickwand --with-project-definition=../freeciv-web.project --enable-fcweb --enable-json --disable-delta-protocol --disable-nls --disable-fcmp --enable-freeciv-manual --disable-ruledit --enable-fcdb=no --enable-ai-static=classic,threaded --prefix=${HOME}/freeciv/ && make -s -j$(nproc)
 )
+
+cp -rfu /tmp/freeciv .  || echo "done"

scripts/install/deb.sh

@@ -18,6 +18,7 @@ dependencies="\
   autoconf \
   automake \
   autotools-dev \
+  build-essential \
   curl \
   git \
   gnupg \
@@ -40,6 +41,7 @@ dependencies="\
   pkg-config \
   pngcrush \
   procps \
+  python \
   python3-minimal \
   python3-pip \
   python3-setuptools \

scripts/install/systems

@@ -4,5 +4,6 @@ Ubuntu	bionic	deb.sh
 Ubuntu	xenial	deb.sh
 Ubuntu	trusty	deb.sh
 Ubuntu	artful	deb.sh
+Ubuntu	focal	deb.sh
 Debian	stretch	deb.sh