Bug#888582: moarvm: FTBFS with debhelper/11.1 due to empty build target

[Niels Thykier]

Source: moarvm
Version: 2017.10+dfsg-1
Severity: serious
Tags: patch

Hi,

The moarvm package FTBFS with debhelper/11.1 as it has an empty build
target.  This is caused by debhelper had a bug in its handling of
"explicitly defined rules targets" that has now been fixed.

Previously, this happened to work because dpkg-buildpackage would
invoke "debian/rules build" (which would be a no-op) followed by
"fakeroot debian/rules binary".  During the binary target, dh's
suboptimal handling would run the build commands.


The solution is trivial but less pretty; explicitly define "build"
with the same content as the "%:" target (or rename the "build" folder
and drop the ".PHONY" target).  I have attached a patch for this.

(There is also a bonus patch for a missing "set -e")


More details can be found in:
 * #886901 comment #35
 * #887688 comment #37
 * #880840

Apologies for the inconvenience.

Thanks,
~Niels
-------------- next part --------------
>From 9a184b3aa2f55cbae6975e4d8bb77b5345e1e30f Mon Sep 17 00:00:00 2001
From: Niels Thykier <niels at thykier.net>
Date: Sat, 27 Jan 2018 12:26:38 +0000
Subject: [PATCH] Avoid empty build target

The dh sequencer as of debhelper/11.1 is stricter with this in other
to solve #880840 (where debhelper would fail to handle such targets
correctly).

Signed-off-by: Niels Thykier <niels at thykier.net>
---
 debian/rules | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/debian/rules b/debian/rules
index 0922da7..b620bf7 100755
--- a/debian/rules
+++ b/debian/rules
@@ -28,6 +28,11 @@ MOAR_LIB_DIR=/usr/lib/moar
 %:
 	dh $@
 
+# The build target must not be empty.  Sadly because of how make
+# works, we have do duplicate the target in this case.
+build:
+	dh $@
+
 override_dh_auto_configure:
 	perl Configure.pl $(CROSS) \
 		--prefix=/usr \
-- 
2.15.1