on at least Linux Mint and Antergos (formerly known as Cinnarch), using version 1.017 (downloaded from SourceForge), installed per-user (~/.local/share/fonts/)... there is no "Regular" style of the fonts; there are, however, two "Medium" styles that are identical. I tried OTF and TTF, both have this issue.

reproduction:

• install OTF or TTF fonts;
• run fc-cache -fv (optionally with sudo);
• try to find Source Code Pro;
• find two Source Code Pro Mediums instead.