Python3.10 source build on CentOS 7.6

The above posts were very helpful to guide me to my solution. I want to share in case someone else could use this:

First the development libs

1. sudo yum groupinstall "Development Tools" -y
2. sudo yum install openssl11-devel libffi-devel bzip2-devel xz-devel -y
   • for static linking use openssl11-static

Then configure

So for some reason CentOS ships openssl1.1.1 but it is installed in a way that doesn't jive with Python's configure script.

# note that we #include <openssl/foo.h>, so the OpenSSL headers have to be in
    # an 'openssl' subdirectory

    if ! $found; then
        OPENSSL_INCLUDES=
        for ssldir in $ssldirs; do
            { $as_echo "$as_me:${as_lineno-$LINENO}: checking for openssl/ssl.h in $ssldir" >&5
$as_echo_n "checking for openssl/ssl.h in $ssldir... " >&6; }
            if test -f "$ssldir/include/openssl/ssl.h"; then
                OPENSSL_INCLUDES="-I$ssldir/include"
                OPENSSL_LDFLAGS="-L$ssldir/lib"
                OPENSSL_LIBS="-lssl -lcrypto"

Since Python is including headers a subfolder is desired: $ssldir/include/openssl/ssl.h

I just created a new folder with the correct layout:

/opt/openssl111/
├── include
│   └── openssl
│       └── *.h
└── lib
    ├── libcrypto.so
    └── libssl.so

Once in place, the trifecta:

1. ./configure --enable-optimizations --with-lto --with-openssl=/opt/openssl111/
   • lto is link time optimization
2. make -j8
3. make altinstall (installs in /usr/local/ not to overwrite system python)