Cross compile fstrim for Android on Ubuntu 18.10

Install compiler

$ sudo apt install gcc-arm-linux-gnueabi 

Get sources and compile

$ apt source util-linux
$ cd util-linux-*
$ ./autogen.sh
$ ./configure --host=arm-linux-gnueabi CFLAGS="-static"
$ make LDFLAGS="--static" fstrim
# OK with warnings

Check

$ file fstrim
fstrim: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, for GNU/Linux 3.2.0, BuildID[sha1]=5f6d5789d8c27197fb5fadbc18f5cd506b330dc4, with debug_info, not stripped