instead it should check for linux once, store that linux is used and not even once check for dylib

strace extract

[pid 23025] stat64("//lib/libreadline.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libreadline.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libreadline.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libreadline.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libreadline.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libreadline.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libreadline.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libreadline.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libreadline.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libreadline.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libreadline.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libreadline.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libreadline.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libreadline.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libreadline.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncursesw.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncursesw.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncursesw.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libncursesw.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libncursesw.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib64/libncursesw.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libncursesw.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libncursesw.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib64/libncursesw.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libncursesw.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libncursesw.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/lib/libncursesw.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libncursesw.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libncursesw.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/lib/libncursesw.a", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncurses.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncurses.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libncurses.a", {st_mode=S_IFREG|0644, st_size=431218, ...}) = 0
[pid 23025] stat64("//lib/libcrypt.dylib", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libcrypt.so", 0xbfd27c1c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libcrypt.a", {st_mode=S_IFREG|0644, st_size=8, ...}) = 0
[pid 23025] stat64("//include/openssl/ssl.h", {st_mode=S_IFREG|0644, st_size=93660, ...}) = 0
[pid 23025] stat64("//include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("./krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("Include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("./Include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/src/Python-2.7.2/Include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/src/Python-2.7.2/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("/usr/kerberos/include/krb5.h", 0xbfd27cac) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libssl.dylib", 0xbfd27b3c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libssl.so", 0xbfd27b3c) = -1 ENOENT (No such file or directory)
[pid 23025] stat64("//lib/libssl.a", {st_mode=S_IFREG|0644, st_size=448496, ...}) = 0