reproducibility: timestamp on generated files; remove random & time env vars

Author: Timothy Kenno Handojo

Diff for: bin/misc-functions.sh

@@ -528,6 +528,10 @@ __dyn_package() {
 		echo -n "${BUILD_ID}" > "${PORTAGE_BUILDDIR}"/build-info/BUILD_ID
 	fi
 
+	if [[ "${BUILD_TIME}" == "ebuild" ]]; then
+		find ${D} -exec touch -h -r ${EBUILD} {} \;
+	fi
+
 	if [[ "${BINPKG_FORMAT}" == "xpak" ]]; then
 		local tar_options=""
 

Diff for: bin/phase-functions.sh

@@ -90,7 +90,7 @@ __filter_readonly_variables() {
 	local bash_misc_vars="BASH BASH_.* COLUMNS COMP_WORDBREAKS HISTCMD
 		HISTFILE HOSTNAME HOSTTYPE IFS LINENO MACHTYPE OLDPWD
 		OPTERR OPTIND OSTYPE POSIXLY_CORRECT PS4 PWD RANDOM
-		SECONDS SHLVL _"
+		SECONDS SHLVL _ SRANDOM EPOCHREALTIME EPOCHSECONDS"
 	local filtered_sandbox_vars="SANDBOX_ACTIVE SANDBOX_BASHRC
 		SANDBOX_DEBUG_LOG SANDBOX_DISABLED SANDBOX_LIB
 		SANDBOX_LOG SANDBOX_ON"