Steps to reproduce on current master (567670bec5ecf9bc252e91370382be53fd81ccee):
# ./configure CC=clang CXX="clang++ -stdlib=libc++"
...
# make V=1
Making all in src
make[1]: Entering directory '/bitcoin/src'
make[2]: Entering directory '/bitcoin/src'
make[3]: Entering directory '/bitcoin'
make[3]: Leaving directory '/bitcoin'
/usr/bin/ccache clang++ -stdlib=libc++ -std=c++17 -DHAVE_CONFIG_H -I. -I../src/config -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -I. -I./secp256k1/include -DBOOST_SP_USE_STD_ATOMIC -DBOOST_AC_USE_STD_ATOMIC -I/usr/include -I./leveldb/include -I./leveldb/helpers/memenv -I./univalue/include -pthread -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -DPROVIDE_FUZZ_MAIN_FUNCTION -fdebug-prefix-map=/bitcoin/src=. -Wstack-protector -fstack-protector-all -Wall -Wextra -Wgnu -Wformat -Wformat-security -Wvla -Wshadow-field -Wswitch -Wthread-safety -Wrange-loop-analysis -Wredundant-decls -Wunused-variable -Wunused-member-function -Wdate-time -Wconditional-uninitialized -Wsign-compare -Woverloaded-virtual -Wunreachable-code-loop-increment -Wno-unused-parameter -Wno-self-assign -Wno-unused-local-typedef -Wno-implicit-fallthrough -fPIE -g -O2 -MT libbitcoin_server_a-httprpc.o -MD -MP -MF .deps/libbitcoin_server_a-httprpc.Tpo -c -o libbitcoin_server_a-httprpc.o `test -f 'httprpc.cpp' || echo './'`httprpc.cpp
In file included from httprpc.cpp:11:
In file included from ./rpc/server.h:11:
In file included from ./rpc/util.h:10:
./outputtype.h:23:38: error: no viable constructor or deduction guide for deduction of template arguments of 'array'
static constexpr auto OUTPUT_TYPES = std::array{
^
/usr/include/c++/v1/__tuple:223:64: note: candidate function template not viable: requires 0 arguments, but 3 were provided
template <class _Tp, size_t _Size> struct _LIBCPP_TEMPLATE_VIS array;
^
/usr/include/c++/v1/__tuple:223:64: note: candidate function template not viable: requires 1 argument, but 3 were provided
1 error generated.
Makefile:8260: recipe for target 'libbitcoin_server_a-httprpc.o' failed
make[2]: *** [libbitcoin_server_a-httprpc.o] Error 1
make[2]: Leaving directory '/bitcoin/src'
Makefile:15489: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/bitcoin/src'
Makefile:820: recipe for target 'all-recursive' failed
make: *** [all-recursive] Error 1
# clang++ --version
clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
