Compiled on RPI3B with 6.1.25-piCore-v7

Compile Flags:
CFLAGS='-march=armv6zk -mtune=arm1176jzf-s -mfpu=vfp -L/usr/local/lib -Os -pipe -flto -fuse-linker-plugin -fno-exceptions'
CXXFLAGS='-march=armv6zk -mtune=arm1176jzf-s -mfpu=vfp -L/usr/local/lib -Os -pipe -flto -fuse-linker-plugin -fno-exceptions -fno-rtti'
LDFLAGS='-Wl,-rpath=/usr/local/lib -Wl,-O1'
export CFLAGS CXXFLAGS LDFLAGS

Dependencies:
compiletc
llvm-bin

Commands:

wget https://archive.mozilla.org/pub/nspr/releases/v4.35/src/nspr-4.35.tar.gz

tar -xf nspr-4.35.tar.gz

cd nspr-4.35/nspr/

./configure --prefix=/usr/local --localstatedir=/var --with-mozilla --with-pthreads

time make -j4
real    1m 20.63s
user    1m 14.49s
sys     0m 6.88s

DESTDIR=/tmp/packing-nspr-dev make install

# These files can be removed
# https://git.alpinelinux.org/aports/tree/main/nspr/APKBUILD?h=3.9-stable
# https://cgit.openembedded.org/openembedded-core/tree/meta/recipes-support/nspr/nspr_4.13.1.bb?h=pyro
rm -f /tmp/packing-nspr-dev/usr/local/bin/prerr.properties
rm -f /tmp/packing-nspr-dev/usr/local/bin/compile-et.pl
rm -fr /tmp/packing-nspr-dev/usr/local/include/nspr/md

# lib, dev
mkdir -p /tmp/packing-nspr/usr/local/lib
mv /tmp/packing-nspr-dev/usr/local/lib/*.so /tmp/packing-nspr/usr/loc

strip --strip-unneeded /tmp/packing-nspr/usr/local/lib/*
llvm-strip --strip-debug /tmp/packing-nspr-dev/usr/local/lib/*.a
sudo chown -R root:root /tmp/packing-nspr /tmp/packing-nspr-dev