Re: [Bug-apl] Cannot find libemacs on older mac

[Alexey Veretennikov]

Hi,

Just to inform what I successfully resolved the issue by running
aclocal, automake and autoconf and reconfiguring && building again.

Br,
/Alexey

Juergen Sauermann <address@hidden> writes:

> Hi Alexey,
>
> GNU APL uses the C functions dlopen() to open the library and dlsym() to 
> locate functions
> inside
> the library.
>
> From the printout we see that GNU APL finds the library file but the dlopen() 
> of the existing file
> fails.
>
> Although the dlopen() and dlsym() functions are quite standard among 
> different platforms, the
> way
> in which the dynamic library files are linked from the compiled object files 
> differs considerably
> between
> platforms.
>
> In this particular case there could be 2 reasons for dlopen() to fail:
>
> 1. a bug in the platform as one of the posts below suggests. Somebody who had 
> the same
> problem (although
> with a different library) has reported that after an OS-X update his problem 
> disappeared.
>
> 2. The library must be constructed in a specific way. On GNU/Linux this is 
> often properly handled
> by libtool,
> but I do not know if libtool even exists on OS-X and if it works properly. On 
> GNU/Linux there is
> another
> tool called libtoolize which prepares autoconf projects that do not use 
> libtoolize into projects
> that do.
> libtoolize does some magic to make shared library work and you may need to do 
> something
> similar on
> your box.
>
> My proposal would be:
>
> 1. upgrade your OS-X as proposed in the post below.
>
> 2. If that does not fix the problem then learn from your platform 
> documentation how shared
> libraries
> for use with dlopen() shall be built. And what namespaces are (they do not 
> exist on GNU/Linux).
>
> Good Luck!
> /// Jürgen
>
> On 12/12/2017 12:27 PM, Alexey Veretennikov wrote:
>
>  Hi,
>
>  Could you please hint me how to specify these flags so I can experiment 
> myself?
>
>  Br,
>  /Alexey
>
>  2017-12-11 16:19 GMT+01:00 Juergen Sauermann <address@hidden>:
>
>  Hi Alexey,
>
>  I suppose that you need some platform specific linker flags when building
>  libemacs.dylib.
>  Since I do not have access to a Mac OS-X machine, I can't tell you which 
> ones.
>
>  Best Regards,
>  /// Jürgen
>
>  On 12/06/2017 08:18 PM, Alexey Veretennikov wrote:
>
>  It is really strange but reporting with otool shows two level:
>
>  otool -hV /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib:
>  Mach header
>  magic cputype cpusubtype caps filetype ncmds sizeofcmds flags
>  MH_MAGIC_64 X86_64 ALL 0x00 DYLIB 14 2272 NOUNDEFS DYLDLINK
>  TWOLEVEL WEAK_DEFINES BINDS_TO_WEAK NO_REEXPORTED_DYLIBS
>
>  For flat libraries there should be no TWOLEVEL flag.
>
>  Br,
>  /Alexey
>
>  2017-12-04 17:33 GMT+01:00 Juergen Sauermann
>  <address@hidden>:
>
>  Hi,
>
>  from the GNU APL printout it looks like the file was found, but something is
>  wrong with the file:
>
>  file /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib ( flat
>  namespace
>  in /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib )
>
>  So GNU APL was able to open the file (using dlopen()) but then gets the
>  "flat namespace" error at some point.
>
>  The second link below says:
>
>  amandogra commented on Oct 2, 2016 
>
>   It got solved by OS upgrade.  
>   For someone who comes to this...  
>   I was on Mac OSX El Capitan, but I upgraded to macOS Sierra.  
>   Then, I executed the following command  
>     
>   brew unlink libevent && brew link libevent  
>     
>   This fixed my issue.  
>
>  The posting was related to a different library but the (rest of the) error
>  message looks very similar (considering
>  that GNU APL cuts off the start the error message text until the last : in 
> it).
>  The full error message was most likely:
> Expected in: flat namespace
>  Maybe "nm -D" on the dylib file reveals some more information.
>
>  Best Regards,
>  /// Jürgen
>
>  On 12/04/2017 04:06 AM, Elias Mårtenson wrote:
>
>  Perhaps adding the path to the dylib file in DYLIB_LIBRARY_PATH will
>  help? Don't forget to exprt the variable before starting apl. 
>
>  Regards,
>  Elias
>
>  On 4 December 2017 at 01:56, Juergen Sauermann
>  <address@hidden> wrote:
>
>  Hi,
>
>  I haven't changed anything in that area. One poster in one of the
>  links below mentioned that an OS-X upgrade
>  had fixed a similar problem that the poster had, so my impression
>  is that this is a problem than cannot be fixed
>  inside GNU APL.
>
>  Best Regards,
>  /// Jürgen 
>
>  On 12/03/2017 12:02 PM, Elias Mårtenson wrote:
>
>  10.6.8 is indeed very old. I thought my Macbook was old and
>  it's running 10.10. 
>
>  I have to admit that I haven't tried the Emacs mode on OSX in
>  a while since I don't use Macs anymore. That said, last time I
>  did try, it worked fine.
>
>  Jürgen, could there be an issue with the way the libraries are
>  built? Did anything change in the last couple of years?
>
>  Regards,
>  Elias
>
>  On 3 December 2017 at 18:58, Juergen Sauermann
>  <address@hidden> wrote:
>
>  Hi Alexey,
>
>  I am not really familiar with emacs or OS X, so Elias is
>  probably better informed than me.
>
>  Unfotunately shared libraries are rather platform
>  dependent and so are the error messages that
>  they produce. From the output below it seems that the
>  file libemacs.dylib exists and was found,
>  but could not be opened with dlopen(). It might be that
>  your platform needs additional linker flags
>  for dynamic libraries to work, but I have no idea which
>  ones.
>
>  See also:
>
>  https://github.com/tmux/tmux/issues/547 or
>
>  
> https://developer.apple.com/library/content/documentation/Porting/Conceptual/PortingUnix/compiling/compiling.html
>  
>
>  Best Regards,
>  /// Jürgen
>
>  On 11/30/2017 08:39 PM, Alexey Veretennikov wrote:
>
>  Hi,
>
>  I've built GNU APL with the following parameters on
>  my old (OSX 10.6.8) macbook:
>
>  ./configure
>  --prefix=/Users/alexey/Applications/gnu-apl
>  make install
>
>  So nothing special(I did a small change though
>  since strndup is not yet supported on this OS). I'm
>  using gcc 7.2.0.
>  However when I try to run apl from emacs, I get the
>  following error:
>
>  Could not find shared library 'libemacs'
>  The following directories and file names were tried:
>  file
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.so
>  (No such file or directory)
>  file
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib
>  ( flat namespace
>  in
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib
>  )
>  file
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs
>  (No such file or directory)
>  directory /usr/lib/apl
>  directory /usr/local/lib/apl
>  file ./libemacs.so (No such file or directory)
>  file ./libemacs.dylib (No such file or directory)
>  file ./libemacs (No such file or directory)
>  directory ./native
>  directory ./emacs_mode
>
>  The file
>  /Users/alexey/Applications/gnu-apl/lib/apl/libemacs.dylib
>  exists.
>
>  Br,
>  /Alexey
>
>

-- 
Br,
/Alexey