Re: [ft] Linking against freetype in Linux

[Kris]

On 26/06/2019 22:59, Lawrence D'Oliveiro wrote:
> On Wed, 26 Jun 2019 22:28:19 +0100, Kris wrote:
>
> > 16892 stat("/usr/lib/gcc/x86_64-linux-gnu/8/libfreetype.so",
> > 0x7ffeecb07830) = -1 ENOENT (No such file or directory)
>
> Why is that "/8/” in the path? That’s not where it is on my Debian
> Unstable system:
>
> ldo@theon:~> ls -l /usr/lib/x86_64-linux-gnu/libfreetype.*
> -rw-r--r-- 1 root root 1055516 Nov 22 2018 
> /usr/lib/x86_64-linux-gnu/libfreetype.a
> lrwxrwxrwx 1 root root      21 Nov 22 2018 
> /usr/lib/x86_64-linux-gnu/libfreetype.so -> libfreetype.so.6.16.1
> lrwxrwxrwx 1 root root      21 Nov 22 2018 
> /usr/lib/x86_64-linux-gnu/libfreetype.so.6 -> libfreetype.so.6.16.1
> -rw-r--r-- 1 root root  763816 Nov 22 2018 
> /usr/lib/x86_64-linux-gnu/libfreetype.so.6.16.1
>
> The unversioned symlink (and .a file) comes from the -dev package, while
> the actual versioned library comes from the runtime package.
>
> Just for fun, would you like to try a simple Python script?
>
>      import ctypes as ct
>      ft = ct.cdll.LoadLibrary("libfreetype.so.6")
>      hasattr(ft, "FT_Init_FreeType")
>
> prints out
>
>      True
>
> on my system.

Doesn't print anything on mine. And to check it was running, I put

print("Before")

and

print("After")

around that last line, to make sure. :)

Using that strace command, and explicitly adding the library path to the 
command line ("-L/usr/lib/x86_64-linux-gnu") gives me the following 
lines at the linker stage:

openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libfreetype.so", O_RDONLY) = 7
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libfreetype.so", O_RDONLY) = 8

These lines DON'T report "ENOENT (No such file or directory)", so with 
that plus the results of the Python script, suggest that the linker is 
opening the libfreetype.so file OK, but then failing to find the symbol 
within it!

Feels like that .so file can't be trusted ... unless it's some 
incompatibility like a 32-bit/64-bit issue? (Just guessing at this point.)

Maybe I should start compiling my own Freetype libraries?

Might try a different Linux distro, too.

Cheers everyone!

Kris.