Notes on the unwanted firefox-bin on Linux

why_Linux_firefox-bin.md

I filed Redhat bug 2342438 that Fedora has an unneeded duplicated firefox-bin in /usr/lib64/firefox/ that is _almost the same binary as /usr/lib64/firefox/firefox.

Likewise there's an unneeded /usr/lib64/thunderbird/thunderbird-bin ([Mozilla bug 697218](https://]

Mozilla bug 658850 has patches that remove mention of firefox-bin from several places, but not the `cp -p in Makefile.in that creates it.

Where do /usr/lib64/firefox/firefox-bin and .../thunderbird-bin come from?

I searched mozilla-central source for everything ending with "-bin" or "x-bin" using the regex [^0-9a-wyz\-]-bin\b]. Here are notes on some of the results.

browser/app/Makefile.in has

ifneq (,$(filter-out WINNT,$(OS_ARCH)))

ifdef COMPILE_ENVIRONMENT
ifndef MOZ_NO_PIE_COMPAT
libs::
	cp -p $(DIST)/bin/$(MOZ_APP_NAME)$(BIN_SUFFIX) $(DIST)/bin/$(MOZ_APP_NAME)-bin$(BIN_SUFFIX)

which copies the binary to -bin as a libs target. There should be a comment explaining this line; why silently make a copy of the MOZ_APP_NAME with -bin on the end?

I looked at a Fedora package build log and in it this copy appears twice, I think because its using PGO and the first time is for an instrumented build. I couldn't figure out how the two binaries end up diverging.

So maybe the fix is not to do this copy by changing the ifdefs, and the -bin file goes away? But other parts of the build reference this file.

mozbuild/artifacts.py lists

   "{product}/{product}-bin",

under class LinuxArtifactJob.

browser/installer/package-manifest.in has various ifndefs that end up adding

#ifndef XP_MACOSX
@BINPATH@/@MOZ_APP_NAME@-bin

I think on Linux this adds firefox-bin to package-manifest.

MOZ_NO_PIE ?

browser/app/moz.build has

    if CONFIG["MOZ_NO_PIE_COMPAT"]:
        GeckoProgram(CONFIG["MOZ_APP_NAME"] + "-bin", linkage=browser_linkage)

I don't know if MOZ_NO_PIE_COMPAT is set in a Linux build.

browser/app/no-pie/NoPie.c defines a main() that reads the executable from /proc/self/exe then appends -bin to it and execv() that path. I'm pretty sure Fedora doesn't do this.

Is the "correct" binary firefox or firefox-bin ?

The firefox(1) man page in the Fedora firefox package describes

firefox is a simple shell script that will set up the environment for the actual executable, firefox-bin. ... /usr/lib64/firefox/firefox-bin - firefox executable

but the shell script wraps /usr/lib64/firefox/firefox, not firefox-bin, so these two lines should be changed. And like the Debian firefox(1) man page it should correctly documents the firefox-bin file as "Legacy executable". I filed Redhat bug 2342756.

The Debian firefox.1 man page says

• /usr/bin/firefox - symbolic link to /usr/lib/firefox/firefox.
• /usr/lib/firefox/firefox - Firefox executable.
• /usr/lib/firefox/firefox-bin - Legacy executable.

But the Linux.die online man page confidently says firefox is a simple shell script that will set up the environment for the actual executable, firefox-bin.

Other things that might depend on -bin executable

I think a bunch of tests hardcode a firefox-bin. There isn't a global "If on system X then append -bin to the binary name".

build.log

I downloaded the build log from a Fedora build.

Line 356022 is the second time it copies the app to app-bin (it builds it twice because it does Profile Guided Optimization): cp -p ../../dist/bin/firefox ../../dist/bin/firefox-bin

Yet somehow one of these is altered after that.

Line 378396 it warns warning: Duplicate build-ids /builddir/build/BUILD/firefox-134.0.2-build/BUILDROOT/usr/lib64/firefox/firefox and /builddir/build/BUILD/firefox-134.0.2-build/BUILDROOT/usr/lib64/firefox/firefox-bin

I can't see any changes to either binary after that, yet they wind up different.