tce-load -i compiletc python3.6 readline-dev rust icu67-dev perl5 llvm-bin autoconf2.13

wget https://download.gnome.org/teams/releng/tarballs-needing-help/mozjs/mozjs-78.0.1gnome.tar.xz

cd mozjs-78.0.1gnome

mkdir mozjs-build
cd mozjs-build

CC="gcc -mtune=generic -Os -pipe" CXX="g++ -mtune=generic -Os -pipe -fno-exceptions -fno-rtti" ../js/src/configure --prefix=/usr/local --enable-readline --with-intl-api --with-system-zlib --with-system-icu --disable-jemalloc --disable-debug-symbols --enable-lto=full

[-flto fails]

find . -name autoconf.mk -type f -exec sed -i 's/-O3//g' {} \;
find . -name backend.mk -type f -exec sed -i 's/-O3//g' {} \;
find . -name autoconf.mk -type f -exec sed -i 's/FLAGS = -g/FLAGS = /g' {} \;
find . -name autoconf.mk -type f -exec sed -i 's/ -g//g' {} \;
find . -name Makefile -type f -exec sed -i 's/-g -O2//g' {} \;

make [17m 8.86s no lto] [19m 29.59s --enable-lto=full]
sudo make install

sudo rm -v /usr/local/lib/libjs_static.ajs
sudo sed -i '/@NSPR_CFLAGS@/d' /usr/local/bin/js78-config