[gentoo-dev] variable quoting, setting optional variables to "", and depending on virtual/libc

[Thomas Cort]

What is the proper quoting style for using epatch? In the tree there
are about 3 different styles...

	epatch ${FILESDIR}/some-fix.patch      # used by 7326 ebuilds
	epatch "${FILESDIR}"/some-fix.patch    # used by 3092 ebuilds
	epatch "${FILESDIR}/some-fix.patch"    # used by 1434 ebuilds

What is the proper quoting style for defining the S variable? In the
tree there are about 3 different styles...

	S=${WORKDIR}/${MY_P}    # used by 5270 ebuilds
	S="${WORKDIR}"/${MY_P}  # used by 43 ebuilds
	S="${WORKDIR}/${MY_P}"  # used by 2259 ebuilds

What is the purpose of setting DEPEND and RDEPEND to "" if DEPEND and
RDEPEND are optional[1][2]? Isn't that just a waste of disk space /
bandwidth? DEPEND="virtual/libc" seems like a waste too as it is an
implicit system dependency[3], any reason for using it?

	DEPEND=""             # used by 1479 ebuilds
	RDEPEND=""            # used by 884 ebuilds
	DEPEND="virtual/libc" # used by 809 ebuilds

[1] http://www.gentoo.org/proj/en/devrel/handbook/handbook.xml?part=2&chap=1#doc_chap_pre2
[2] http://devmanual.gentoo.org/ebuild-writing/variables/index.html#optional-variables
[3] http://devmanual.gentoo.org/general-concepts/dependencies/index.html#implicit-system-dependency