Cannot install on Fedora 26/27 using Python 3.6

[ludbb]

Cannot install on Fedora 26/27 using Python 3.6

[pch957]

seems you don't have command 'make'
try install make

[ppitonak]

make is available. It seems that this package cannot be installed using Python 3.6 (default) but it works with 3.5

[Wallacoloo]

I can confirm this bug on Arch Linux. Installing this library via pip on Python3.5 succeeds, presumably because it uses a prebuilt package as stated in the Readme, but installing via pip on Python3.6 triggers a build of the C library which fails as shown above by @ppitonak.

$ gcc --version
gcc (GCC) 7.2.1 20171224
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

To highlight the build error:

    /tmp/pip-build-p8qbm3sp/secp256k1/libsecp256k1/src/tests.c: In function ‘test_ecdsa_der_parse’:
    /tmp/pip-build-p8qbm3sp/secp256k1/libsecp256k1/src/tests.c:3702:52: error: dereferencing pointer to incomplete type ‘ECDSA_SIG {aka struct ECDSA_SIG_st}’
             valid_openssl = !BN_is_negative(sig_openssl->r) && !BN_is_negative(sig_openssl->s) && BN_num_bits(sig_openssl->r) > 0 && BN_num_bits(sig_openssl->r) <= 256 && BN_num_bits(sig_openssl->s) > 0 && BN_num_bits(sig_openssl->s) <= 256;

I wouldn't be surprised if it's somehow tied to us using a newer version of gcc than the libsecp256k1 devs which handles this error differently.

[Uxio0]

I see that there are recompiled binary wheels available for Python 2.7, 3.3, 3.4, and 3.5 on Linux. Would be awesome to have it too for Python 3.6

[xjia1]

Please see #24 (comment) for a workaround.