but does this for debug builds:
export SQLITE3_CFLAGS="-fPIC \
—> Thx for spotting my mistake.
Most (all?) C compilers ignore CFLAGS, as they expect build flags on the command line. It's the configure script that captures the value of CFLAGS and modifies the various build control files accordingly.
—> You're correct that the configure script sets the command-line options to compile the code.