Re: Can't build TclTLS 2.0b1

* Ashok <apnmbx-public@yahoo.com>
| So I'm guessing that /usr/include is already in the default system
| include search path and therefore gets ignored when specified as the
| -I
| option. Additionally, /usr/local/include appears before /usr/include
| in the default search path. That might explain what you are seeing.

  https://stackoverflow.com/questions/4980819/what-are-the-gcc-default-include-directories

suggests to use

  echo | gcc -xc -E -v -

to see the defaults plus any effect of environment variables like CPATH

  % echo | gcc -xc -E -v -
  [...]
    #include "..." search starts here:
    #include <...> search starts here:
     /usr/lib64/gcc/x86_64-suse-linux/7/include
     /usr/local/include
     /usr/lib64/gcc/x86_64-suse-linux/7/include-fixed
     /usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/include
     /usr/include
    End of search list.

So indeed /usr/local/include is listed *before* /usr/include.

One could use -isystem/usr/include to change that order:

  % echo | gcc -isystem/usr/include -xc -E -v -
  [...]
    #include "..." search starts here:
    #include <...> search starts here:
     /usr/include
     /usr/lib64/gcc/x86_64-suse-linux/7/include
     /usr/local/include
     /usr/lib64/gcc/x86_64-suse-linux/7/include-fixed
     /usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/include
    End of search list.


HTH
R'