Mac OS 10.15 Catalina issues

I find an issue( which is exactly the problem I am facing. Yes, I need to download the CLT from After I install the CLT, run command brew config

Anyway, the problem was fixed, thank you for your kindly help bro.


Is anyone able to install Python2 while running Catalina?

When running:

brew install python@2

I get the following error:

ln -fsn Versions/Current/Python Python.framework/Python

ln -fsn Versions/Current/Headers Python.framework/Headers

ln -fsn Versions/Current/Resources Python.framework/Resources

clang -isysroot /Applications/ -u _PyMac_Error Python.framework/Versions/2.7/Python -o python.exe \

                                            Modules/python.o \

                                            -ldl  -framework CoreFoundation

DYLD_FRAMEWORK_PATH=/private/tmp/python@2-20190827-29454-1pwlkv6/Python-2.7.16 ./python.exe -E -S -m sysconfig --generate-posix-vars ;\

            if test $? -ne 0 ; then \

                            echo "generate-posix-vars failed" ; \

                            rm -f ./pybuilddir.txt ; \

                            exit 1 ; \


/bin/sh: line 1: 35581 Segmentation fault: 11 DYLD_FRAMEWORK_PATH=/private/tmp/python@2-20190827-29454-1pwlkv6/Python-2.7.16 ./python.exe -E -S -m sysconfig --generate-posix-vars

generate-posix-vars failed

make: *** [pybuilddir.txt] Error 1

Anyone have any thoughts?

Looks like ?

It looks like gettext won’t build under Xcode 11 (tried beta 6 and beta 7). Spews this:

ftello.c:53:12: error: no member named '_flag' in 'struct __sFILE'; did you mean '_flags'?
  if (fp_->_flag & _IOWRT)
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/_stdio.h:130:8: note: '_flags' declared here
        short   _flags;         /* flags, below; this FILE is free if 0 */
ftello.c:53:20: error: use of undeclared identifier '_IOWRT'
  if (fp_->_flag & _IOWRT)
ftello.c:64:21: error: no member named '_flag' in 'struct __sFILE'; did you mean '_flags'?
          if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL)
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/include/_stdio.h:130:8: note: '_flags' declared here
        short   _flags;         /* flags, below; this FILE is free if 0 */
ftello.c:64:50: error: no member named '_base' in 'struct __sFILE'
          if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL)
                                            ~~~  ^
ftello.c:65:25: error: no member named '_ptr' in 'struct __sFILE'
            pos += fp_->_ptr - fp_->_base;
                   ~~~  ^
ftello.c:65:37: error: no member named '_base' in 'struct __sFILE'
            pos += fp_->_ptr - fp_->_base;
                               ~~~  ^
6 errors generated.

Since gettext is a dependency of ungodly lots of stuff, this hurts.

I’m not too proficient in C and macOS SDK differences to dig into it deeper, sorry.

An update. Guess I figured out the cause, but still no idea how to fix it.

The configure script for the gnulib component, which replaces “broken” libc functions with its own versions, checks for some undesired behavior of ftell(). It detects that on macOS, if you open a file in “r+” mode, read it up to EOF (by fseek()ing to its end, really), write one more byte, and call ftell() on it, the reported position will be wrong — the file pointer needs to advance as you write more data. There seems to be a known bug on Solaris, just like that.

So the configure script sets a variable telling that ftell() is broken on this system, but gnulib only has a replacement for Solaris, which uses the struct __sFILE as found there, and predictably barfs because __sFILE on Darwin is nothing like that.

How healthy an approach to patching systems that misbehave is left as an exercise to the reader, but here’s one thing: up to and including Mojave, ftell() was working just fine, and the replacement was never needed. Maybe, hm, someone more in the know should report it to Apple before they make a release?

XCode 11 beta 6 (haven’t tried beta 7) also makes openssl@1.0 segfault. A function accepts a pointer; at the callsite, it’s NULL, but in the function itself, it’s something bogus, which, upon dereferencing, gives a segfault. No idea whatsoever how that compiled. :-/

CLT for XCode Beta 7 seem to be unavailable ( Let’s see what tomorrow brings.

I had to downgrade back down to beta 6 as it cause conflicts for me when I upgraded to 7

newbie here, with clt 11 GM brew don’t see xcode-select and keep requesting installing it.

Have you tried installing Xcode from the developer site then run brew config

yes I did. I had to revert to beta 6 to have homwbrew see my clr

I was able to build gettext by setting FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE to 0 as described here:

But… ftell() really doesn’t work correctly (per assumptions) on Catalina. You can check that by running the very test program gettext itself is using — ftell() fails expectations. The particular problem with gettext is that it then proceeds to apply a workaround for Solaris, using definitions from the Solaris’ guts.

You can of course set that variable, doesn’t mean your program won’t corrupt your data in the runtime because of this ftell() behavior.

Python now builds successfully on the latest Catalina public beta. I’m not sure if that’s a change in Catalina or somewhere in the Python code, but I’m no longer getting the error when getttext builds.

@johnbrady833 python2 or 3?

First time I tried to install Homebrew, so not sure if it is a Catalina problem or something else. Maybe someone could tell me by looking at the error message? Thanks!

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This seems more like a connection issue.

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Both python2 and 3 built OK for me.

Have a look at point number 7 on

I downloaded the Command Line Developer Tools directly from apple, installed them and then i could install brew as usual. but the script inside the brew-installation which gave you those tools could not fetch those, through it seems, that the Command Line Tools aren’t available from the softwareupdate-mechanism at the moment.

I have a such error message. And I have Catalina too

If you want to deploy brew with macOS 10.15 Catalina, you should consider using the script from rtrouton ( to install the command line tools:

This script provides a general solution to install the command line tools without any userinteraction. So in general you could deploy this script to any user who needs those tools.