Patch for Python 3.4.x for macos, based on https://bugs.python.org/issue28676

Python-3.4.3-macos.patch

diff --git a/Python/random.c b/Python/random.c
index 93d300d..396041d 100644
--- a/Python/random.c
+++ b/Python/random.c
@@ -3,6 +3,9 @@
 #include <windows.h>
 #else
 #include <fcntl.h>
+#if defined(HAVE_GETRANDOM) || defined(HAVE_GETENTROPY)
+#include <sys/random.h>
+#endif
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif

I got it to work. I had to do this, notice the lack of a version stamp

brew uninstall --ignore-dependencies --force openssl

Then...

brew reinstall zlib

and finally.

CPPFLAGS="-I/usr/local/opt/zlib/include -I$(brew --prefix readline)/include" LDFLAGS="-L$(brew --prefix readline)/lib -L/usr/local/opt/zlib/lib" pyenv install 3.4.3 --patch < Python-3.4.3-macos.patch

Where Python-3.4.3-macos.path is @karthicraghupathi version (thank you so much).

diff --git a/Python/random.c b/Python/random.c
index 93d300d..396041d 100644
--- a/Python/random.c
+++ b/Python/random.c
@@ -3,6 +3,9 @@
 #include <windows.h>
 #else
 #include <fcntl.h>
+#if defined(HAVE_GETRANDOM) || defined(HAVE_GETENTROPY)
+#include <sys/random.h>
+#endif
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
 diff --git a/Misc/NEWS.d/next/macOS/2020-06-24-13-51-57.bpo-41100.mcHdc5.rst b/Misc/NEWS.d/next/macOS/2020-06-24-13-51-57.bpo-41100.mcHdc5.rst
new file mode 100644
index 0000000000000..ded66b567a92d
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2020-06-24-13-51-57.bpo-41100.mcHdc5.rst
@@ -0,0 +1 @@
+Support macOS 11 when building.
diff --git a/configure b/configure
index c51f396824b63..5024860ca4395 100755
--- a/configure
+++ b/configure
@@ -3426,7 +3426,7 @@ $as_echo "#define _BSD_SOURCE 1" >>confdefs.h
   # has no effect, don't bother defining them
   Darwin/[6789].*)
     define_xopen_source=no;;
-  Darwin/1[0-9].*)
+  Darwin/[12][0-9].*)
     define_xopen_source=no;;
   # On AIX 4 and 5.1, mbstate_t is defined only when _XOPEN_SOURCE == 500 but
   # used in wcsnrtombs() and mbsnrtowcs() even if _XOPEN_SOURCE is not defined
diff --git a/configure.ac b/configure.ac
index 70deefb6b9aea..5a3e340aa3e72 100644
--- a/configure.ac
+++ b/configure.ac
@@ -510,7 +510,7 @@ case $ac_sys_system/$ac_sys_release in
   # has no effect, don't bother defining them
   Darwin/@<:@6789@:>@.*)
     define_xopen_source=no;;
-  Darwin/1@<:@0-9@:>@.*)
+  Darwin/@<:@[12]@:>@@<:@0-9@:>@.*)
     define_xopen_source=no;;
   # On AIX 4 and 5.1, mbstate_t is defined only when _XOPEN_SOURCE == 500 but
   # used in wcsnrtombs() and mbsnrtowcs() even if _XOPEN_SOURCE is not defined

Thanks everyone! I would have been lost without this page. Afterwords i reinstalled openssl.

@DuncanTormey your solution was the only one that worked for me (I did it with 3.4.10 btw). Thank you 💪

@DuncanTormey, your solution was the only one that worked for me too..... thank you so much!!

@DuncanTormey your solution was only one that worked for me too.... thank you sooooo much