Following Alexander's post on installing 5.0.0rc3 under Android/Termux, I would like to share some additional observations in the hope that some might find them useful.
You can get shorten the installation steps if you build Chicken in a chrooted Termux. In the chroot environment, all the standard directories are in the standard places and writable, rendering the LD_LIBRARY_PATH configuration superfluous.
$ make PLATFORM=android C_COMPILER=clang PREFIX=/usr
$ make PLATFORM=android C_COMPILER=clang PREFIX=/usr install
And you should be done.
In summary, prior to installing Chicken Scheme in Termux, install PRoot, `pkg install proot', run termux-chroot to get a chrooted environment, then proceed with the build.
A note of caution: this will install the files under the root directory, so you can't have multiple versions side by side. For this reason, I actually did something slightly different than the procedure described above. I've kept the prefix to my home directory, like Alexander, so I have Chicken 5.0.0rc3 installed in $HOME/chickens/5.0.0rc3, and Chicken 4.13.0 in $HOME/chickens/4.13.0.
I then created a symbolic link called current that points to the version I want to use. For example, $HOME/chickens/current points to $HOME/chickens/5.0.0rc3.
Finally, I've created symbolic links in /usr/bin, /usr/lib, /usr/include and /usr/share referring to the current Chicken distribution (the files under $HOME/chickens/current). This is a one-time, manual process. When I want to switch between Chicken versions, I just change where `current' points to.
In the end, this may have been overdoing it, and I am not at all sure that I would recommend this setup over fiddling with .bashrc to achieve the same results.
By the way, `chicken-doc' is not available with 5.0.0rc3, so I've reverted to 4.13.0 because Geiser complains without it.