building much, much faster – python 3.8 beta 4 on the rpi4b/4GB

Nearly a year ago I wrote about building Python 3.7.0 on a Raspberry Pi 3B+ with Raspbian 9.4 ( One key highlight was how much time it took to build including any testing, which was two to three hours. I build Python 3.8.0 beta 4 on the Raspberry Pi 4B, on the SSD, and it took around 30 minutes (I say around, because I wasn’t paying much attention and certainly wasn’t timing it). When it finished I installed it in a folder on the SSD as well, and then started some minor testing on my own.

If you’re going to do something like this, then make sure that after an install you remove all soft links bin directory. The bin directory should look something like this:

All those links will end in a ‘3’, such as ‘python3’, and if you have the path to where you installed the Python 3.8 beta binaries in your overall $PATH, then you’ll pick it up instead of the default. So remove those links for the time being and instead use python3.8 when you want to test.

One more minor detail, which I started doing when building Qt5, and that’s create a build folder away from the source folder. Configure and build out of the build folder, so that if you need to rebuild with different configuration or different features, it’s simple to just create a second separate build folder and run everything again. For example:

Everything is in the build folder instead of commingled in with all the source. I wrote in last year’s post to build inside the source code folder after you unpacked it, and that was poor advice on my part.

A Tipping Point

The Raspberry Pi 4, in spite of its few rough edges (excess heat generation, non-standard USB C power connector) is still an excellent development platform, especially at US $55 for the 4GB version. With the drop in price of solid state storage prices you can build a very good Raspbian development system and do all your work natively instead of cross-compiling on another system (Linux or macOS or Windows 10). It keeps costs down considerably, especially if you’re on a budget. Even if you’re not, it’s still an excellent bargain all around. If you want to purchase a Raspberry Pi, then the 4B with 4GB is the one to get. With the extensive ecosystem and user community that’s built up around the Raspberry Pi, there’s no longer any excuse to hold back.