[BUG] bootstrap.sh fail on Mac OS

[pan-]

Describe the bug
The cryptography and cmsis python package used by Mbed OS are not trivial to install on Mac OS:

• They require Cargo and rust to be installed
• Open SSL is required to build the wheel, depending on the package manager used and its configuration, the environment variable will change: https://cryptography.io/en/latest/installation.html .

To Reproduce
./bootstrap.sh on MacOS.

Expected behavior

• Instructions to install the third party dependencies.
• Setup of environment variable when pip is invoked depending on whether MacOS is used or not.

[noonfom]

Is this not an Mbed OS issue? I mean cryptography and cmsis-pack-manager are pulled in here.

[noonfom]

Indeed it fails on Mac OS with Python 3.8+. However, the issue is a result of the Mbed OS cryptography version being incompatible with 3.8+, not Mac OS.

As a workaround, we can edit the Mbed OS requirements in bootstrap.sh:

# Edit Mbed OS cryptography requirement for Python 3.8+
sed -i '' 's/cryptography>=2.5,<3/cryptography/' dependencies/mbed-os/requirements.txt

It may also be required to specify a Click version > 7.1