#55 %set_build_flags: add LT_SYS_LIBRARY_PATH
Opened 5 months ago by praiskup. Modified 2 months ago
rpms/ praiskup/redhat-rpm-config LT_SYS_LIBRARY_PATH  into  master

file modified
+6 -3

@@ -15,9 +15,9 @@ 

  `--prefix=/usr`) to adjust the paths to the packaging defaults.


  As a side effect, this will set the environment variables `CFLAGS`,

- `CXXFLAGS`, `FFLAGS`, `FCFLAGS`, and `LDFLAGS`, so they can be used by

- makefiles and other build tools.  (However, existing values for this

- variables are not overwritten.)


+ so they can be used by makefiles and other build tools.  (However,

+ existing values for these variables are not overwritten.)


  If your package does not use autoconf, you can still set the same

  environment variables using

@@ -43,6 +43,9 @@ 

    driver.  At the start of the `%build` section, the environment

    variable `RPM_LD_FLAGS` is set to this value.


+ The variable `LT_SYS_LIBRARY_PATH` is defined here to prevent the `libtool`

+ script (v2.4.6+) from hardcoding %_libdir into the binaries' RPATH.


  These RPM macros do not alter shell environment variables.


  For some other build tools separate mechanisms exist:

file modified
+3 -1

@@ -50,12 +50,14 @@ 

  # variables CFLAGS, CXXFLAGS, FFLAGS, FCFLAGS, LDFLAGS if they have

  # not been set already.  RPM_OPT_FLAGS and RPM_LD_FLAGS have already

  # been set implicitly at the start of the %%build section.

+ # LT_SYS_LIBRARY_PATH is used by libtool script.

  %set_build_flags \

    CFLAGS="${CFLAGS:-%{build_cflags}}" ; export CFLAGS ; \

    CXXFLAGS="${CXXFLAGS:-%{build_cxxflags}}" ; export CXXFLAGS ; \

    FFLAGS="${FFLAGS:-%{build_fflags}}" ; export FFLAGS ; \

    FCFLAGS="${FCFLAGS:-%{build_fflags}}" ; export FCFLAGS ; \

-   LDFLAGS="${LDFLAGS:-%{build_ldflags}}" ; export LDFLAGS

+   LDFLAGS="${LDFLAGS:-%{build_ldflags}}" ; export LDFLAGS ; \



  # Internal-only.  Do not use.  Expand a variable and strip the flags

  # not suitable to extension builders.

The libtool script/macros (new enough, v2.4.6+) honor this
variable in cases where it isn't possible to detect the
system-wide default library path. It is e.g. able to parse
/etc/ld.so.* configuration, but there's no info about /usr/lib64.

So to not force everybody to do:

%configure LT_SYS_LIBRARY_PATH=...

... rather set this system-wide. Note that this is low-risk
change; older libtool doesn't use this variable, and really no
other tool should.

to me, this belongs to %configure and not to %set_build_flags

I don't know. @fweimer do you agree with @ignatenkobrain on that point?

FTR, there also exists a system-wide hack for older libtool scripts:

rebased onto fc5cc06abf1c4b250f3cdb83dc894c4ee87297d8

5 months ago

As %set_build_flags can be (and is quite often) used outside of the context of %configure, I have to agree with @ignatenkobrain. Certainly it's just a random environment variable and shouldn't cause issues, but it doesn't seem like it belongs with the build flags.

(And while looking into this, I realize that%cmake should probably use %set_build_flags instead of the similar but slightly different thing it uses currently.)

rebased onto 53690d2aef656331be79b43505b3bf0a5d954c32

5 months ago

I don't disagree with Igor here except that in %configure there are no variables set these days so I was not sure. Moved to %configure, thanks for taking a look.

Is LT_SYS_LIBRARY_PATH an environment variable, or something that is processed by the autoconf script?

It is environment variable which is processed by ./configure script (not by autoconf itself). Not sure whether it answers your question... When the variable is set during ./configure phase, the built ./libtool has different defaults for sys_lib_dlsearch_path.

Well, plus the LT_SYS_LIBRARY_PATH is also env variable accepted by ./libtool script (at the time of ./libtool run, it overrides the default set by ./configure).

That said, even if the package doesn't run %configure but uses libtool, it can be useful to have that variable set in environment.

If it is an environment variable picked up by libtool, setting LT_SYS_LIBRARY_PATH in %set_build_flags seems the correct thing to do.

Would you please add a comment that LT_SYS_LIBRARY_PATH affects libtool to the macros file, and also update buildflags.md. Thanks.

rebased onto 3284ed0cc7473016649f2cad5edccf21bea79f18

4 months ago

rebased onto bc3609f4e70710e9d9ab1eb3cad25dcb1a02eb00

4 months ago

Maybe this? … not to hardcode %_libdir into the RPATH attribute of ELF binaries

Either “The LT_SYS_LIBRARY_PATH variable is …” or “LT_SYS_LIBRARY_PATH is …”.

Technically neither are quite correct. If we're going to be that picky:

The variable `LT_SYS_LIBRARY_PATH` is defined here to prevent the `libtool` script (v2.4.6+) from hardcoding %_libdir into the binaries' RPATH.

Thanks for comments! Updated.

rebased onto 5accde152871ca6f32c6e4064b1e0627208817c4

4 months ago

rebased onto e1fd368

2 months ago