[PATCH input-vmmouse] tools: make install fails when user has no write permission in /lib

[Peter Hutterer]

On Mon, Sep 30, 2013 at 11:59:57PM -0400, Gaetan Nadon wrote:
> On 13-09-30 06:24 PM, Peter Hutterer wrote:
> > On Mon, Sep 30, 2013 at 01:56:53PM -0400, Gaetan Nadon wrote:
> >> The location of the udevdir is obtained from pkg-config. This is generally
> >> /lib/udev. Most people run their build scripts as non-root and do not want to
> >> overwrite or add files on their workstation system.
> >>
> >> This was not the behaviour in release 12.8.0. The code in configure.ac set
> >> udevdir based on common installation prefixes /usr or /usr/local for which
> >> the user would probably have root permission anyway. Other prefixes would
> >> be assigned a udevdir value under the given $prefix.
> >>
> >> The patch proposes the default location $libdir/udev/rules.d and no longer
> >> seeking it's value from pkg-config, just like what was done for hal.
> > is udevdir to be retired? iirc HAL never exported this as a variable
> > hence the hardcoded path, but I think relying on the udev package to tell
> > you where to look for data is the correct approach.
> The only usage of $udevdir is for the installation of the rules file,
> which must be done under $prefix. If one needs to get information from
> the real workstation  system udev, then yes, the corect approach would
> be to look in lib/udev/rules.d obtained from from pkg-config. However, I
> have not seen any such activity in any of the makefiles of C code.
> 
> With the current git code, the problem is reversed. If I configure the
> module to install the rules file under $prefix, then I would be no
> longer able to "look for data" in the system udev.
> 
> There are always two directories, the one under $prefix, and the real
> system directory which is mirrored by $prefix. Consider binaries and
> libraries. They install under $prefix, but can access other system bins
> and libs through environment variables that are providing an ordered
> path of locations. No such thing with udev.
> 
> From the man page:
> 
>     Rules files
>            The udev rules are read from the files located in the default
>     rules
>            directory /lib/udev/rules.d/, the custom rules directory
>            /etc/udev/rules.d/ and the temporary rules directory
>            /run/udev/rules.d/. All rule files are collectively sorted and
>            processed in lexical order, regardless of the directories in
>     which they
>            live. However, files in /etc/udev/rules.d/ take precedence
>     over files
>            with the same name in /lib/udev/rules.d/; this can be used to
>     ignore a
>            default rules file if needed.
> 
> These alternate location also require root access, so no help there.
> 
> I think the patch is correct and is an improvement over the current
> code, but it does not address the "two directories" situation, the real
> one vs the $prefix one. If my assumption that there is no need to query
> the real udev system is correct, then the patch is all we need.

ok, fair enough. but that brings up the next question: $libdir is /usr/lib,
right? so if you want to install into /lib/udev/rules.d you need something
else than $libdir. On Fedora that's the same directory nowadays, but on
other distros /lib and /usr/lib are separate.

Cheers,
   Peter


> 
> >
> > your patch has two changes: remove udev pkgconfig bits and change the
> > default. I agree with the latter, it seems the right thing to do, but not
> > the former.
> The former is still an open issue which the patch has slightly changed
> its manifestation.
> >
> > Cheers,
> >    Peter
> >
> >
> >> The expectation is that the xorg source tree can be built from top to bottom
> >> out of the box without tweaks or workarounds. A developer need to
> >> manually install a rule under development and run an admin command for it to
> >> take effect. Unlike binaries or libraries, there is no "path" style
> >> variable to append a rule in development from a different location.
> >>
> >> Signed-off-by: Gaetan Nadon <memsize at videotron.ca>
> >> ---
> >>  configure.ac |   15 ++++++---------
> >>  1 file changed, 6 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/configure.ac b/configure.ac
> >> index 52ea460..83a8488 100644
> >> --- a/configure.ac
> >> +++ b/configure.ac
> >> @@ -91,17 +91,14 @@ AC_ARG_WITH(hal-fdi-dir,
> >>  HAL_FDI_DIR=${halfdidir}
> >>  AC_SUBST(HAL_FDI_DIR)
> >>  
> >> -
> >> -PKG_CHECK_MODULES(UDEV, udev,
> >> -                  [UDEV_RULES_DIR="`$PKG_CONFIG --variable=udevdir udev`/rules.d"],
> >> -                  [UDEV_RULES_DIR=no])
> >> -
> >> +# Udev location for rules directory
> >>  AC_ARG_WITH(udev-rules-dir,
> >>  	    AS_HELP_STRING([--with-udev-rules-dir=DIR],
> >> -			   [Default udev rules.d directory
> >> -			    [[default=($prefix)/lib/udev/rules.d on Linux, none otherwise]]]),
> >> -	    [UDEV_RULES_DIR="$withval"],
> >> -	    [])
> >> +			   [Directory where udev expects its rules files
> >> +			   [[default=$libdir/udev/rules.d]]]),
> >> +	    [udevdir="$withval"],
> >> +	    [udevdir="$libdir/udev/rules.d"])
> >> +UDEV_RULES_DIR=${udevdir}
> >>  AC_SUBST(UDEV_RULES_DIR)
> >>  AM_CONDITIONAL(HAS_UDEV_RULES_DIR, [test "x$UDEV_RULES_DIR" != "xno"])
> >>  
> >> -- 
> >> 1.7.9.5
> >>
>