The compiler normally uses crt1.o
combined with crt[i/n].o and crt[begin/end].o to support the constructors and destructors (functions called before and after main and exit).
This error could be caused by this missing library file for the specific deployment target.
First, do some investigation, like:
List all your deployment targets:
ls -la /Developer/SDKs
Find which crt1
libraries do you have for which environment
find /Developer/SDKs -name crt1\*
You could see something like:
/Developer/SDKs/MacOSX10.5.sdk/usr/lib/crt1.10.5.o
/Developer/SDKs/MacOSX10.5.sdk/usr/lib/crt1.o
/Developer/SDKs/MacOSX10.6.sdk/usr/lib/crt1.10.5.o
/Developer/SDKs/MacOSX10.6.sdk/usr/lib/crt1.10.6.o
/Developer/SDKs/MacOSX10.6.sdk/usr/lib/crt1.o
As you can see in above example, crt1.10.6.o
is missing for MacOSX10.5.
Solution 1
You can solve that by creating the link to the missing file pointed to the other environment, or you could change your deployment target.
E.g.
ln -s /Developer/SDKs/MacOSX10.6.sdk/usr/lib/crt1.10.6.o /Developer/SDKs/MacOSX10.5.sdk/usr/lib/
Other reason why it's missing, is that you could have different gcc
installed in your system. E.g.:
which gcc
xcrun -find gcc
brew list | grep gcc; brew list gcc47
Solution 2
So when you're compiling using make, you can actually specify the right compiler by CC variable. E.g.
CC=/path/to/gcc-3.4 make
Solution 3
What you can also try is specifying the right target deployment environment variable for gcc, e.g.:
export MACOSX_DEPLOYMENT_TARGET=10.5
If this works, then you can add this library path to your shell profile (~/.profile
).
E.g.
export C_INCLUDE_PATH=/Developer/SDKs/MacOSX10.5.sdk/usr/include
export LIBRARY_PATH=/Developer/SDKs/MacOSX10.5.sdk/usr/lib
Or by temporary exporting them.
How to test
Create the example conftest.c
file with the following code:
#ifdef __GNUC__
yes;
#endif
And try to compile it via:
gcc conftest.c
cc conftest.c
cc conftest.cc conftest.c