[PATCH for 4.6 v2] configure: don't silently disable systemd support

[PATCH for 4.6 v2] configure: don't silently disable systemd support

[Wei Liu]

Originally when user runs ./configure --enable-systemd and systemd
development library is not available the build system silently disables
systemd support. This is not in line with normal expectation.

Instead, configure should error out when user has asked for systemd
support but development libraries can't be found.

Reported-by: George Dunlap <george.dunlap@eu.citrix.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
v2: invert the test to check for explicit "yes" value.

Please rerun ./autogen.sh.
---
 m4/systemd.m4 | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/m4/systemd.m4 b/m4/systemd.m4
index 8284993..e4b1aa5 100644
--- a/m4/systemd.m4
+++ b/m4/systemd.m4
@@ -85,7 +85,11 @@ AC_DEFUN([AX_CHECK_SYSTEMD], [
 		AC_DEFINE([HAVE_SYSTEMD], [1], [Systemd available and enabled])
 			systemd=y
 			AX_CHECK_SYSTEMD_LIBS()
-	    ],[systemd=n])
+	    ],[
+		AS_IF([test "x$enable_systemd" = "xyes"],
+			[AC_MSG_ERROR([Unable to find systemd development library])],
+			[systemd=n])
+	    ])
 	],[systemd=n])
 ])
 
-- 
2.1.4

Re: [PATCH for 4.6 v2] configure: don't silently disable systemd support

[Ian Campbell]

On Thu, 2015-09-10 at 12:18 +0100, Wei Liu wrote:
> Originally when user runs ./configure --enable-systemd and systemd
> development library is not available the build system silently disables
> systemd support. This is not in line with normal expectation.
> 
> Instead, configure should error out when user has asked for systemd
> support but development libraries can't be found.
> 
> Reported-by: George Dunlap <george.dunlap@eu.citrix.com>
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>

Acked + applied to staging + staging-4.6

> ---
> v2: invert the test to check for explicit "yes" value.
> 
> Please rerun ./autogen.sh.
> ---
>  m4/systemd.m4 | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/m4/systemd.m4 b/m4/systemd.m4
> index 8284993..e4b1aa5 100644
> --- a/m4/systemd.m4
> +++ b/m4/systemd.m4
> @@ -85,7 +85,11 @@ AC_DEFUN([AX_CHECK_SYSTEMD], [
>  		AC_DEFINE([HAVE_SYSTEMD], [1], [Systemd available and
> enabled])
>  			systemd=y
>  			AX_CHECK_SYSTEMD_LIBS()
> -	    ],[systemd=n])
> +	    ],[
> +		AS_IF([test "x$enable_systemd" = "xyes"],
> +			[AC_MSG_ERROR([Unable to find systemd
> development library])],
> +			[systemd=n])
> +	    ])
>  	],[systemd=n])
>  ])
>  

Re: [PATCH for 4.6 v2] configure: don't silently disable systemd support

[Ian Jackson]

Ian Campbell writes ("Re: [PATCH for 4.6 v2] configure: don't silently disable systemd support"):
> On Thu, 2015-09-10 at 12:18 +0100, Wei Liu wrote:
> > Originally when user runs ./configure --enable-systemd and systemd
> > development library is not available the build system silently disables
> > systemd support. This is not in line with normal expectation.
> > 
> > Instead, configure should error out when user has asked for systemd
> > support but development libraries can't be found.
> > 
> > Reported-by: George Dunlap <george.dunlap@eu.citrix.com>
> > Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> 
> Acked + applied to staging + staging-4.6

FTR:

I do not think this is a good backport candidate.  Changes to the
behaviour of build configuration machinery are a bad idea in stable
branches.

(AFAIK no-one has requested a backport of this but I thought I should
make a note of my thoughts.)

Ian.