grpc-rs: grpc-sys 0.4.2 fails to build - but 0.4.1 builds fine

Describe the bug

0.4.2 fails to build for us with CentOS 7.

To Reproduce

On CentOS 7 run cargo build against a crate which depends on either grpc-sys 0.4.2, or grpc-sys 0.4.1

With grpc-sys 0.4.2, the following is seen:

error: failed to run custom build command for `grpcio-sys v0.4.2`
process didn't exit successfully: `/target/debug/build/grpcio-sys-840781b2e44e9c86/build-script-build` (exit code: 101)
--- stdout
cargo:rerun-if-changed=grpc_wrap.cc
cargo:rerun-if-changed=grpc
cargo:rerun-if-env-changed=GRPCIO_SYS_USE_PKG_CONFIG
cargo:rerun-if-env-changed=CARGO_CFG_TARGET_OS
running: "cmake" "/opt/rust/registry/src/github.com-1ecc6299db9ec823/grpcio-sys-0.4.2/grpc" "-DGO_EXECUTABLE=fake-go-nonexist" "-DgRPC_INSTALL=false" "-DgRPC_BUILD_CSHARP_EXT=false" "-DgRPC_BUILD_CODEGEN=false" "-DCMAKE_INSTALL_PREFIX=.../target/debug/build/grpcio-sys-f45f9c164b4a8726/out" "-DCMAKE_C_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_C_COMPILER=/usr/local/bin/cc" "-DCMAKE_CXX_FLAGS= -ffunction-sections -fdata-sections -fPIC -m64" "-DCMAKE_CXX_COMPILER=/usr/bin/c++" "-DCMAKE_BUILD_TYPE=Debug"
-- The C compiler identification is GNU 4.8.5
-- The CXX compiler identification is GNU 4.8.5
-- Check for working C compiler: /usr/local/bin/cc
-- Check for working C compiler: /usr/local/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Looking for sys/types.h
-- Looking for sys/types.h - found
-- Looking for stdint.h
-- Looking for stdint.h - found
-- Looking for stddef.h
-- Looking for stddef.h - found
-- Check size of off64_t
-- Check size of off64_t - done
-- Looking for fseeko
-- Looking for fseeko - found
-- Looking for unistd.h
-- Looking for unistd.h - found
-- Renaming
--     /opt/rust/registry/src/github.com-1ecc6299db9ec823/grpcio-sys-0.4.2/grpc/third_party/zlib/zconf.h
-- to 'zconf.h.included' because this file is included with zlib
-- but CMake generates it automatically in the build directory.
-- Looking for res_servicename in resolv
-- Looking for res_servicename in resolv - not found
-- Looking for gethostbyname in nsl
-- Looking for gethostbyname in nsl - found
-- Looking for gethostbyname in socket
-- Looking for gethostbyname in socket - not found
-- Looking for clock_gettime in rt
-- Looking for clock_gettime in rt - found
-- Looking for include file sys/socket.h
-- Looking for include file sys/socket.h - found
-- Looking for include file arpa/inet.h
-- Looking for include file arpa/inet.h - found
-- Looking for include file arpa/nameser_compat.h
-- Looking for include file arpa/nameser_compat.h - found
-- Looking for include file arpa/nameser.h
-- Looking for include file arpa/nameser.h - found
-- Looking for include file assert.h
-- Looking for include file assert.h - found
-- Looking for include file errno.h
-- Looking for include file errno.h - found
-- Looking for include file fcntl.h
-- Looking for include file fcntl.h - found
-- Looking for include file inttypes.h
-- Looking for include file inttypes.h - found
-- Looking for include file limits.h
-- Looking for include file limits.h - found
-- Looking for include file malloc.h
-- Looking for include file malloc.h - found
-- Looking for include file memory.h
-- Looking for include file memory.h - found
-- Looking for include file netdb.h
-- Looking for include file netdb.h - found
-- Looking for include file netinet/in.h
-- Looking for include file netinet/in.h - found
-- Looking for include file netinet/tcp.h
-- Looking for include file netinet/tcp.h - found
-- Looking for include file net/if.h
-- Looking for include file net/if.h - found
-- Looking for include file signal.h
-- Looking for include file signal.h - found
-- Looking for include file socket.h
-- Looking for include file socket.h - not found
-- Looking for include file stdbool.h
-- Looking for include file stdbool.h - found
-- Looking for include file stdlib.h
-- Looking for include file stdlib.h - found
-- Looking for include file strings.h
-- Looking for include file strings.h - found
-- Looking for include file string.h
-- Looking for include file string.h - found
-- Looking for include file stropts.h
-- Looking for include file stropts.h - not found
-- Looking for include file sys/ioctl.h
-- Looking for include file sys/ioctl.h - found
-- Looking for include file sys/param.h
-- Looking for include file sys/param.h - found
-- Looking for include file sys/select.h
-- Looking for include file sys/select.h - found
-- Looking for include file sys/stat.h
-- Looking for include file sys/stat.h - found
-- Looking for include file sys/time.h
-- Looking for include file sys/time.h - found
-- Looking for include file sys/uio.h
-- Looking for include file sys/uio.h - found
-- Looking for include file time.h
-- Looking for include file time.h - found
-- Looking for include file dlfcn.h
-- Looking for include file dlfcn.h - found
-- Looking for include file unistd.h
-- Looking for include file unistd.h - found
-- Looking for include files winsock2.h, windows.h
-- Looking for include files winsock2.h, windows.h - not found
-- Looking for 3 include files winsock2.h, ..., windows.h
-- Looking for 3 include files winsock2.h, ..., windows.h - not found
-- Looking for include files winsock.h, windows.h
-- Looking for include files winsock.h, windows.h - not found
-- Looking for include file windows.h
-- Looking for include file windows.h - not found
-- Performing Test HAVE_SOCKLEN_T
-- Performing Test HAVE_SOCKLEN_T - Success
-- Performing Test HAVE_TYPE_SOCKET
-- Performing Test HAVE_TYPE_SOCKET - Failed
-- Performing Test HAVE_BOOL_T
-- Performing Test HAVE_BOOL_T - Success
-- Performing Test HAVE_SSIZE_T
-- Performing Test HAVE_SSIZE_T - Success
-- Performing Test HAVE_LONGLONG
-- Performing Test HAVE_LONGLONG - Success
-- Performing Test HAVE_SIG_ATOMIC_T
-- Performing Test HAVE_SIG_ATOMIC_T - Success
-- Performing Test HAVE_STRUCT_ADDRINFO
-- Performing Test HAVE_STRUCT_ADDRINFO - Success
-- Performing Test HAVE_STRUCT_IN6_ADDR
-- Performing Test HAVE_STRUCT_IN6_ADDR - Success
-- Performing Test HAVE_STRUCT_SOCKADDR_IN6
-- Performing Test HAVE_STRUCT_SOCKADDR_IN6 - Success
-- Performing Test HAVE_STRUCT_SOCKADDR_STORAGE
-- Performing Test HAVE_STRUCT_SOCKADDR_STORAGE - Success
-- Performing Test HAVE_STRUCT_TIMEVAL
-- Performing Test HAVE_STRUCT_TIMEVAL - Success
-- Looking for AF_INET6
-- Looking for AF_INET6 - found
-- Looking for O_NONBLOCK
-- Looking for O_NONBLOCK - found
-- Looking for FIONBIO
-- Looking for FIONBIO - found
-- Looking for SIOCGIFADDR
-- Looking for SIOCGIFADDR - found
-- Looking for MSG_NOSIGNAL
-- Looking for MSG_NOSIGNAL - found
-- Looking for PF_INET6
-- Looking for PF_INET6 - found
-- Looking for SO_NONBLOCK
-- Looking for SO_NONBLOCK - not found
-- Looking for CLOCK_MONOTONIC
-- Looking for CLOCK_MONOTONIC - found
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID - Success
-- Performing Test HAVE_LL
-- Performing Test HAVE_LL - Success
-- Looking for bitncmp
-- Looking for bitncmp - not found
-- Looking for closesocket
-- Looking for closesocket - not found
-- Looking for CloseSocket
-- Looking for CloseSocket - not found
-- Looking for connect
-- Looking for connect - found
-- Looking for fcntl
-- Looking for fcntl - found
-- Looking for freeaddrinfo
-- Looking for freeaddrinfo - found
-- Looking for getaddrinfo
-- Looking for getaddrinfo - found
-- Looking for getenv
-- Looking for getenv - found
-- Looking for gethostbyaddr
-- Looking for gethostbyaddr - found
-- Looking for gethostbyname
-- Looking for gethostbyname - found
-- Looking for gethostname
-- Looking for gethostname - found
-- Looking for getnameinfo
-- Looking for getnameinfo - found
-- Looking for getservbyport_r
-- Looking for getservbyport_r - found
-- Looking for gettimeofday
-- Looking for gettimeofday - found
-- Looking for if_indextoname
-- Looking for if_indextoname - found
-- Looking for inet_net_pton
-- Looking for inet_net_pton - not found
-- Looking for inet_ntop
-- Looking for inet_ntop - found
-- Looking for inet_pton
-- Looking for inet_pton - found
-- Looking for ioctl
-- Looking for ioctl - found
-- Looking for ioctlsocket
-- Looking for ioctlsocket - not found
-- Looking for IoctlSocket
-- Looking for IoctlSocket - not found
-- Looking for recv
-- Looking for recv - found
-- Looking for recvfrom
-- Looking for recvfrom - found
-- Looking for send
-- Looking for send - found
-- Looking for setsockopt
-- Looking for setsockopt - found
-- Looking for socket
-- Looking for socket - found
-- Looking for strcasecmp
-- Looking for strcasecmp - found
-- Looking for strcmpi
-- Looking for strcmpi - not found
-- Looking for strdup
-- Looking for strdup - found
-- Looking for stricmp
-- Looking for stricmp - not found
-- Looking for strncasecmp
-- Looking for strncasecmp - found
-- Looking for strncmpi
-- Looking for strncmpi - not found
-- Looking for strnicmp
-- Looking for strnicmp - not found
-- Looking for writev
-- Looking for writev - found
-- Found Perl: /usr/bin/perl (found version "5.16.3") 
-- The ASM compiler identification is GNU
-- Found assembler: /usr/local/bin/cc
-- Configuring done
-- Generating done
-- Build files have been written to: .../target/debug/build/grpcio-sys-f45f9c164b4a8726/out/build

--- stderr
CMake Warning at cmake/protobuf.cmake:48 (message):
  gRPC_PROTOBUF_PROVIDER is "module" but PROTOBUF_ROOT_DIR is wrong
Call Stack (most recent call first):
  CMakeLists.txt:140 (include)


CMake Warning at cmake/gflags.cmake:26 (message):
  gRPC_GFLAGS_PROVIDER is "module" but GFLAGS_ROOT_DIR is wrong
Call Stack (most recent call first):
  CMakeLists.txt:142 (include)


CMake Warning at cmake/benchmark.cmake:26 (message):
  gRPC_BENCHMARK_PROVIDER is "module" but BENCHMARK_ROOT_DIR is wrong
Call Stack (most recent call first):
  CMakeLists.txt:143 (include)


CMake Error at CMakeLists.txt:738 (target_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:CXX>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:6171 (target_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:CXX>

  Expression did not evaluate to a known generator expression
....
thread 'main' panicked at '
command did not execute successfully, got: exit code: 1

build script failed, must exit now', /opt/rust/registry/src/github.com-1ecc6299db9ec823/cmake-0.1.35/src/lib.rs:778:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.

warning: build failed, waiting for other jobs to finish...
error: failed to verify package tarball

Caused by:
  build failed

Expected behavior

grpc-sys to build successfully.

System information

• CPU architecture: x86-64
• Distribution and kernel version: CentOS 7 under Docker on Core OS.
• SELinux on?:
• Any other system details we should know?:

Additional context Add any other context about the problem here.