Can't build fonts on Debian 11 Bullseye

[Doc73]

Dear dev, when I try to build the font, I get this error:

$ make
Generating  build/EBGaramond08-Regular.otf
make: python: No such file or directory
make: *** [Makefile:53: build/EBGaramond08-Regular.otf] Error 127

All dependencies are installed:

$ apt policy python3-fontforge ttfautohint 
python3-fontforge:
  Installed: 1:20201107~dfsg-4
  Candidate: 1:20201107~dfsg-4
  Version table:
 *** 1:20201107~dfsg-4 500
        500 http://deb.debian.org/debian bullseye/main amd64 Packages
        100 /var/lib/dpkg/status
ttfautohint:
  Installed: 1.8.3-2+b1
  Candidate: 1.8.3-2+b1
  Version table:
 *** 1.8.3-2+b1 500
        500 http://deb.debian.org/debian bullseye/main amd64 Packages
        100 /var/lib/dpkg/status

Maybe the above libraries are old?

[Doc73]

Yes, now it works, but I get several warnings like this:

Lookup subtable contains unused glyph iotatonos.sc making the whole subtable invalid

[Doc73]

Ok! Perfect!