latest version of some snapshot artifact. If m2 is offline, SCM operations
  cannot succeed; no artifact downloads can take place, regardless of whether
  they are snapshot versions; artifact deployment cannot take place; certain
  types of tests cannot be setup, since the container used to run them cannot be
  reached or started.

which the executable runs, unless that component itself accompanies the
executable.

If distribution of executable or object code is made by offering access
to copy from a designated place, then offering equivalent access to copy
the source code from the same place counts as distribution of the source
code, even though third parties are not compelled to copy the source
along with the object code.