Fast fail on missing tools

[AVee]

Versions

• Python: 3.7
• OS: Windows 10 + WSL + Debian Buster
• Buildozer: 1.0

Description

Buildozer does a bunch of checks for the presence of required programs when starting but fails to check for the presence of a unzip command:

# Run 'unzip -q /home/avee/.buildozer/android/platform/android-sdk/sdk-tools-linux-4333796.zip'
# Cwd /home/avee/.buildozer/android/platform/android-sdk
# Command failed: unzip -q /home/avee/.buildozer/android/platform/android-sdk/sdk-tools-linux-4333796.zip
...
(env) avee@localhost:~$ unzip
-bash: unzip: command not found

Obviously that's easily fixed by installing unzip, but it would be nice if buildozer would fail early.

For some missing tools there are warnings:

[WARNING]: Missing executable: autoconf is not installed
[WARNING]: Missing executable: automake is not installed
[WARNING]: Missing executable: libtoolize is not installed

It would be nice if those would fail as well, at least in a default run (I can see the use of something like an --ignore-missing-executables flag). Failing fast on relatively trivial things like this can save a lot of time when setting up a build environment (especially when doing it for the first time).

Command:
buildozer android debug

[AVee]

And the same goes for the zip command. (Only finding that out a 2 hours later illustrates the point...)

[AndreMiras]

Yes that would be nice, not only with executables, but also other build dependencies e.g. libraries.
Pull requests are welcome

[Julian-O]

Note: Do not perform this check when running Windows. unzip isn't used in that case (even though Windows support isn't there yet)

buildops.checkbin() makes this an easy feature to add.