OSX 10.10.5 git clone latest master (19be26afe3d04783a92d032b55bf3fb1e2ae63cc)
I’m not sure what happened because I’ve been able to compile bitcoin from source on this machine recently until today.
I’ve seen on other issues that openssl might be the issue:
 0$ brew info openssl
 1openssl: stable 1.0.2k (bottled) [keg-only]
 2SSL/TLS cryptography library
 3https://openssl.org/
 4/usr/local/Cellar/openssl/1.0.2j (1,695 files, 12M)
 5  Poured from bottle on 2016-10-04 at 10:12:41
 6/usr/local/Cellar/openssl/1.0.2k (1,696 files, 12M)
 7  Poured from bottle on 2017-03-06 at 15:09:14
 8From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/openssl.rb
 9==> Dependencies
10Build: makedepend ✘
11==> Options
12--universal
13	Build a universal binary
14--without-test
15	Skip build-time tests (not recommended)
16==> Caveats
17A CA file has been bootstrapped using certificates from the SystemRoots
18keychain. To add additional certificates (e.g. the certificates added in
19the System keychain), place .pem files in
20  /usr/local/etc/openssl/certs
21
22and run
23  /usr/local/opt/openssl/bin/c_rehash
24
25This formula is keg-only, which means it was not symlinked into /usr/local.
26
27Apple has deprecated use of OpenSSL in favor of its own TLS and crypto libraries
28
29If you need to have this software first in your PATH run:
30  echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bash_profile
31
32For compilers to find this software you may need to set:
33    LDFLAGS:  -L/usr/local/opt/openssl/lib
34    CPPFLAGS: -I/usr/local/opt/openssl/include
35For pkg-config to find this software you may need to set:
36    PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig
… but I did set those flags (output of configure):
 0Options used to compile and link:
 1  with wallet   = yes
 2  with gui / qt = no
 3  with zmq      = no
 4  with test     = yes
 5  with bench    = yes
 6  with upnp     = yes
 7  debug enabled = no
 8  werror        = no
 9
10  target os     = darwin
11  build os      = darwin
12
13  CC            = gcc
14  CFLAGS        = -g -O2
15  CPPFLAGS      = -I/usr/local/opt/openssl/include -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -I/usr/local/opt/berkeley-db@4/include -DMAC_OSX
16  CXX           = g++ -std=c++11
17  CXXFLAGS      = -g -O2 -Wall -Wextra -Wformat -Wvla -Wformat-security -Wshadow -Wno-unused-parameter -Wno-self-assign -Wno-unused-local-typedef -Wno-deprecated-register
18  LDFLAGS       = -L/usr/local/opt/openssl/lib -Wl,-headerpad_max_install_names -Wl,-dead_strip