Developers looking for another alternative to Google's ecosystem but who still want an Android app-compatible experience can now create their own flashable build of Sailfish OS for Sony's Xperia X. That's thanks to a newly released set of build assets announced by Jolla via the company's official blog several days back which the firm refers to as "Hardware Adaptation sources and instructions." The announcement also appears to be completely separate from earlier talks about selling Sailfish OS directly, meaning that the OS can be had for free as long as anybody wanting to flash it has the appropriate level of skill and is willing to put up with one or two problems that currently exist in the OS.
As to the aforementioned issues with Sailfish OS on the Sony Xperia X, there are around six which may prove problematic for some users. Each is currently somewhat solvable or is being worked on, but they are something people should be aware of before getting started. First, input using Fingerterm is slow. There is a fix available, but it won't be in the OS itself until the next update. Bluetooth is also currently broken. A partial fix for that has been found but is still being integrated. The fingerprint sensor, step counter, and barometer are also not functioning at this time, and neither is mobile data tethering. There is not currently a fix for those issues. Beyond that, there are currently problems with both video recording and video playback which are being worked on. Finally, the OS only utilizes two CPU cores by default. Bearing all of that in mind, and with consideration for the processes involved, it bears mentioning that getting Sailfish OS up and running through the newly announced build instructions is a somewhat elongated process. Users are to undertake the task at their own risk and are advised against proceeding if they aren't absolutely sure about what they're doing.
With all of that said, the point of making the build guide and assets public is described by Jolla as a way to accelerate the development of the OS itself through a more open-source approach. Developers can contribute back to the project's repositories, with some changes possibly being incorporated into Sailfish OS in later updates. Better still, it should be possible to add Sailfish OS to other handsets falling under Sony's Open Devices umbrella by following guidance from the #sailfishos-porters Freenode IRC channel linked below.