**Installing MacPorts on Ubuntu Linux**

----

MacPorts has been designed to be multi-platform, and it does install on Ubuntu Linux with modest modifications. Please note that at this point in time, this is a highly experimental process, and issues are expected to arise.

First, some quick notes for those familiar with Darwin;   on Ubuntu:

apt is the built-in package manager, similar to "port".

"sudo apt install" is similar to "sudo port install".

"apt info" is similar to "port info"

"apt-file show" does something similar to "port contents", but the software does not have to be installed.

"dpkg -S /path/to/file" does something similar to "port provides"



** Note: there has been a conflict noted with {{{libmd-dev}}} when installing base; just disable that temporarily to install MacPorts. There could be other conflicts not yet discovered. **

To install MacPorts on Ubuntu Linux, you must first install the necessary prerequisites that are typically found on Darwin systems. At the time of writing, this was:
{{{
sudo apt install clang-14
sudo apt install clang
sudo apt install mtree-netbsd
sudo apt install tcl8.6
sudo apt install curl
sudo apt install sqlite3
sudo apt install gnustep
sudo apt install libcurl4-gnutls-dev
sudo apt install libsqlite3-dev
sudo apt install libssl-dev
}}}
or, all at once:
{{{
sudo apt install clang-14 clang mtree-netbsd tcl8.6 curl sqlite3 gnustep libcurl4-gnutls-dev libsqlite3-dev libssl-dev
}}}


Then download the macports tarball  from macports.org, perhaps using the included FireFox browser, and decompress it, as per the usual Darwin instructions <https://www.macports.org/install.php#source>. 

I suggest that you don't install startup items at this point in time, as this functionality is different on Ubuntu, so configure your build like this:
{{{
./configure --without-startupitems
}}}
and then 
{{{
make && sudo make install
}}}

Then add the "macports" user, in the Ubuntu way:
{{{
sudo adduser --system --group --home /opt/local/var/macports/home  --disabled-password macports
sudo chown -R macports:macports /opt/local/var/macports/home
}}}

Add the macports directory to your PATH as usual, but on Ubuntu, by editing ".bashrc", for example with {{{nano}}}, adding a line like this:
{{{
export PATH=/opt/local/bin:/opt/local/sbin:$PATH
}}}

Also add that PATH to the sudo command's path, like this:
{{{
sudo visudo
}}}
and add it to the secure_path
{{{
Defaults  secure_path="/opt/local/bin:/opt/local/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"
}}}
There are some differences between Darwin and Ubuntu, and to work around some of these that are not already compensated for by MacPorts base, set some defaults in {{{macports.conf}}} like this:

{{{
sudo gedit /opt/local/etc/macports/macports.conf
}}}
and add:
{{{
default_compilers      clang            # compiler selection is not yet working on Ubuntu, this chooses /usr/bin/clang which works best with macport's portfiles
cxx_stdlib             libstdc++        # configure.cxx_stdlib is not yet working on Ubuntu, this fills in appropriate default
}}}

Darwin and Ubuntu supply 'sed' and 'grep' in different locations, so rather than edit many Portfiles that expect it in the Darwin location, you can do this:
{{{
sudo ln -s /bin/sed /usr/bin/sed
sudo ln -s /bin/grep /usr/bin/grep
}}}

And at that point, you should be able to run normal MacPorts commands. 
{{{
sudo port -v selfupdate
}}}
will update your ports tree to the current status.

And then try to install a typical port, like this:
{{{
sudo port -v install libffi
}}}

And presto:
{{{
$ port -v installed
The following ports are currently installed:
  libffi @3.2.1_0 (active) platform='linux 5' archs='x86_64' date='2020-05-02T23:25:44-0700
}}}

You can certainly expect to come across issues; MacPorts' PortFiles have largely been written to assume they are installing on Darwin, but with minor modifications to some ports, seem happy with Linux as well.