Do not try to execute enter-env.sh on anything other than bash.
Do not try to execute enter-env.sh on anything other than bash.

Also try to use return first on two first errors
as we do not know yet if we are being sourced or not.

mithro/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware