Build problem with gcc-10.2 (Beyond Linux From Scratch 10.0) built on LFS-10.0)

[DrHarlan]

The make output for ptlib-master is attached. Gcc is 10.2.0 and the problem seems to come when an openssl include file, ossl_typ.h, is used. I'm not very knowledgable in C++, but it may be that openssl is contributing to this.
ptlib-build.txt
If you need any additional info let me know.

[mwberry]

As far as I can tell, this package is written to compile against OpenSSL 1.0, which is very old. Your linux distribution may or may not have it available as a package. If it does, it may or may not be in the location that the compiler is looking for it.

I found that I had to explicitly point pkgconf at OpenSSL 1.0 to get past these errors:

$ PKG_CONFIG_PATH=/usr/lib/openssl-1.0/pkgconfig pkg-config --path openssl
/usr/lib/openssl-1.0/pkgconfig/openssl.pc
$ PKG_CONFIG_PATH=/usr/lib/openssl-1.0/pkgconfig pkg-config --cflags --libs openssl
-I/usr/include/openssl-1.0 -L/usr/lib/openssl-1.0 -lssl -lcrypto 
$ PKG_CONFIG_PATH=/usr/lib/openssl-1.0/pkgconfig:/usr/lib/pkgconfig ./configure

However that only gets me to the next compile error.

...
+ g++ -I/root/ptlib/include -DP_64BIT -DPTRACING=1 -D_REENTRANT -I/usr/include/openssl-1.0 -fno-exceptions -Wall -Wformat -Wfo
rmat-security -D_FORTIFY_SOURCE=2 -DP_64BIT -fPIC -DPIC -DNDEBUG -Os -felide-constructors -Wreorder -c ptlib/unix/svcproc.cxx 
-o /root/ptlib/lib_linux_x86_64/obj/svcproc.o
...
ptlib/unix/svcproc.cxx:387:33: error: call of overloaded ‘basic_ifstream(PString&)’ is ambiguous
  387 |     ifstream pidfile(pidfilename);
      |                                 ^
/usr/include/c++/12.2.0/fstream:567:7: note: candidate: ‘std::basic_ifstream<_CharT, _Traits>::basic_ifstream(const std::string&, std::ios_base::openmode) [with _CharT = char; _Traits = std::char_traits<char>; std::string = std::__cxx11::basic_string<char>; std::ios_base::openmode = std::ios_base::openmode]’
  567 |       basic_ifstream(const std::string& __s,
      |       ^~~~~~~~~~~~~~
/usr/include/c++/12.2.0/fstream:534:7: note: candidate: ‘std::basic_ifstream<_CharT, _Traits>::basic_ifstream(const char*, std::ios_base::openmode) [with _CharT = char; _Traits = std::char_traits<char>; std::ios_base::openmode = std::ios_base::openmode]’
  534 |       basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
      |       ^~~~~~~~~~~~~~

This is on:

commit 27b403a0e0928c3bd83810a7b9b00ea08308d6a2 (HEAD -> master, tag: v2.10.15, origin/master, origin/HEAD)
Author: Pete Davidson <[email protected]>
Date:   Thu May 26 20:00:46 2016 -0400

    Version 2.10.15

On a system with glibc 2.36 and gcc 12.2.0.