debian: support a "chg-first" installation mechanism (hg is actually chg)
authorKyle Lippincott <spectral@google.com>
Thu, 04 Feb 2021 17:34:20 -0800
changeset 46629 90481550467c
parent 46628 0a23ace80e54
child 46630 842f2372ced6
debian: support a "chg-first" installation mechanism (hg is actually chg) This mechanism builds chg such that it looks for `hg` to be available at /usr/lib/mercurial/hg instead of in the $PATH as `hg`, and makes the `hg` in /usr/bin be a symlink to `chg`. It's important to note that the hg binary must continue to be named `hg`. If we wanted to instead place it at /usr/bin/pyhg or something similar, we would need to modify Mercurial to allow that basename. Failure to do so would break Mercurial's shell aliases that use `hg`, `chg`, or `$HG`. I don't know if we should ever have a setup like this be the default setup, but I'm willing to get more information on our experience with it for making such a determination. Actually making it the default might be rather involved, as we don't maintain the official debian packaging rules. Differential Revision: https://phab.mercurial-scm.org/D10020
contrib/packaging/debian/rules
--- a/contrib/packaging/debian/rules	Thu Mar 04 00:31:18 2021 +0100
+++ b/contrib/packaging/debian/rules	Thu Feb 04 17:34:20 2021 -0800
@@ -18,6 +18,10 @@
 #   DEB_HG_PYTHON_VERSIONS="3.7 3.8" make deb
 DEB_HG_MULTI_VERSION?=0
 
+# Set to 1 to make /usr/bin/hg a symlink to chg, and move hg to
+# /usr/lib/mercurial/hg.
+DEB_HG_CHG_BY_DEFAULT?=0
+
 CPUS=$(shell cat /proc/cpuinfo | grep -E ^processor | wc -l)
 
 # By default, only build for the version of python3 that the system considers
@@ -40,6 +44,12 @@
 	DEB_HG_PYTHON_VERSIONS?=$(shell py3versions -vd)
 endif
 
+ifeq ($(DEB_HG_CHG_BY_DEFAULT), 1)
+	# Important: the "real" hg must have a 'basename' of 'hg'. Otherwise, hg
+	# behaves differently when setting $HG and breaks aliases that use that.
+	export HGPATH=/usr/lib/mercurial/hg
+endif
+
 export HGPYTHON3=1
 export PYTHON=python3
 
@@ -86,3 +96,8 @@
 	cp contrib/bash_completion "$(CURDIR)"/debian/mercurial/usr/share/bash-completion/completions/hg
 	mkdir -p "$(CURDIR)"/debian/mercurial/usr/share/zsh/vendor-completions
 	cp contrib/zsh_completion "$(CURDIR)"/debian/mercurial/usr/share/zsh/vendor-completions/_hg
+	if [[ "$(DEB_HG_CHG_BY_DEFAULT)" -eq 1 ]]; then \
+		mkdir -p "$(CURDIR)"/debian/mercurial/usr/lib/mercurial; \
+		mv "$(CURDIR)"/debian/mercurial/usr/bin/hg "$(CURDIR)"/debian/mercurial/usr/lib/mercurial/hg; \
+		ln -s chg "$(CURDIR)"/debian/mercurial/usr/bin/hg; \
+	fi