I have only a pretty basic knowledge of Linux operating systems, though I am usually able to find solutions to my problems online, however in this case I have been completely unsuccessful. I'm pasting the code in but there's a lot of it and I am unsure what is relevant or irrelevant so sorry about that. Any help would be greatly appreciated. Cheers.

anthony@anthony-Aspire-ES1-411:~/citra/build$ cmake ../
-- The C compiler identification is GNU 7.0.1
-- The CXX compiler identification is GNU 7.0.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Target architecture: x86_64
-- Boost 1.63.0 or newer not found, falling back to externals
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Check if compiler accepts -pthread
-- Check if compiler accepts -pthread - yes
-- Found Threads: TRUE
<FindSDL2.cmake>
</FindSDL2.cmake>
-- Found SDL2: /usr/lib/x86_64-linux-gnu/libSDL2main.a;/usr/lib/x86_64-linux-gnu/libSDL2.so;-pthread
-- Check if the system is big endian
-- Searching 16 bit integer
-- 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 unsigned short
-- Check size of unsigned short - done
-- Using unsigned short
-- Check if the system is big endian - little endian
-- Target architecture: x86_64
-- Boost version: 1.64.0
-- CMake version: 3.7.2
-- Version: 3.0.2
-- Build type:
-- Performing Test HAVE_STD_CPP11_FLAG
-- Performing Test HAVE_STD_CPP11_FLAG - Success
-- Performing Test FMT_CPP11_CMATH
-- Performing Test FMT_CPP11_CMATH - Success
-- Performing Test FMT_CPP11_UNISTD_H
-- Performing Test FMT_CPP11_UNISTD_H - Success
-- Performing Test FMT_CPP11_SNPRINTF
-- Performing Test FMT_CPP11_SNPRINTF - Success
-- Performing Test SUPPORTS_VARIADIC_TEMPLATES
-- Performing Test SUPPORTS_VARIADIC_TEMPLATES - Success
-- Performing Test SUPPORTS_INITIALIZER_LIST
-- Performing Test SUPPORTS_INITIALIZER_LIST - Success
-- Performing Test SUPPORTS_ENUM_BASE
-- Performing Test SUPPORTS_ENUM_BASE - Success
-- Performing Test SUPPORTS_TYPE_TRAITS
-- Performing Test SUPPORTS_TYPE_TRAITS - Success
-- Performing Test SUPPORTS_USER_DEFINED_LITERALS
-- Performing Test SUPPORTS_USER_DEFINED_LITERALS - Success
-- Looking for open
-- Looking for open - found
-- Looking for fcntl
-- Looking for fcntl - found
-- Looking for poll
-- Looking for poll - found
-- Looking for getaddrinfo
-- Looking for getaddrinfo - found
-- Looking for getnameinfo
-- Looking for getnameinfo - found
-- Looking for gethostbyname_r
-- Looking for gethostbyname_r - found
-- Looking for gethostbyaddr_r
-- Looking for gethostbyaddr_r - found
-- Looking for inet_pton
-- Looking for inet_pton - found
-- Looking for inet_ntop
-- Looking for inet_ntop - found
-- Performing Test HAS_MSGHDR_FLAGS
-- Performing Test HAS_MSGHDR_FLAGS - Success
-- Check size of socklen_t
-- Check size of socklen_t - done
-- C++ Requests CMake Options
-- =======================================================
-- USE_SYSTEM_CURL: OFF
-- BUILD_CPR_TESTS: OFF
-- GENERATE_COVERAGE: OFF
-- CPR_CURL_NOSIGNAL: OFF
-- USE_SYSTEM_GTEST: OFF
-- CMAKE_USE_OPENSSL: ON
-- =======================================================
-- Not using system Curl, using built-in curl project instead.
CMake Warning at externals/cpr/opt/curl/CMakeLists.txt:49 (message):
the curl cmake build system is poorly maintained. Be aware


-- curl version=[7.52.1-DEV]
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_ADDR
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_ADDR - Success
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
-- Performing Test HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID - Success
Found *nroff option: -- -man
-- Looking for dlopen in dl;
-- Looking for dlopen in dl; - found
-- Looking for connect in socket;dl
-- Looking for connect in socket;dl - not found
-- Looking for gethostbyname in c
-- Looking for gethostbyname in c - found
-- Looking for gethostname
-- Looking for gethostname - found
-- Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the system variable OPENSSL_ROOT_DIR (missing: OPENSSL_LIBRARIES OPENSSL_INCLUDE_DIR)
-- Looking for ldap_init in ldap;dl
-- Looking for ldap_init in ldap;dl - not found
-- Looking for ber_init in lber;dl
-- Looking for ber_init in lber;dl - not found
-- Looking for include file ldap.h
-- Looking for include file ldap.h - not found
-- Looking for include file lber.h
-- Looking for include file lber.h - not found
-- LDAP_H not found CURL_DISABLE_LDAP set ON
-- LDAP needs to be enabled to support LDAPS
-- Looking for idn2_lookup_ul in idn2;dl
-- Looking for idn2_lookup_ul in idn2;dl - not found
-- Looking for dlopen in dl
-- Looking for dlopen in dl - found
-- Could NOT find LibSSH2 (missing: LIBSSH2_INCLUDE_DIR LIBSSH2_LIBRARY)
-- Performing Test USE_UNIX_SOCKETS
-- Performing Test USE_UNIX_SOCKETS - Success
-- Looking for include file stdio.h
-- Looking for include file stdio.h - found
-- Looking for include files stdio.h, inttypes.h
-- Looking for include files stdio.h, inttypes.h - found
-- Looking for 3 include files stdio.h, ..., sys/filio.h
-- Looking for 3 include files stdio.h, ..., sys/filio.h - not found
-- Looking for 3 include files stdio.h, ..., sys/ioctl.h
-- Looking for 3 include files stdio.h, ..., sys/ioctl.h - found
-- Looking for 4 include files stdio.h, ..., sys/param.h
-- Looking for 4 include files stdio.h, ..., sys/param.h - found
-- Looking for 5 include files stdio.h, ..., sys/poll.h
-- Looking for 5 include files stdio.h, ..., sys/poll.h - found
-- Looking for 6 include files stdio.h, ..., sys/resource.h
-- Looking for 6 include files stdio.h, ..., sys/resource.h - found
-- Looking for 7 include files stdio.h, ..., sys/select.h
-- Looking for 7 include files stdio.h, ..., sys/select.h - found
-- Looking for 8 include files stdio.h, ..., sys/socket.h
-- Looking for 8 include files stdio.h, ..., sys/socket.h - found
-- Looking for 9 include files stdio.h, ..., sys/sockio.h
-- Looking for 9 include files stdio.h, ..., sys/sockio.h - not found
-- Looking for 9 include files stdio.h, ..., sys/stat.h
-- Looking for 9 include files stdio.h, ..., sys/stat.h - found
-- Looking for 10 include files stdio.h, ..., sys/time.h
-- Looking for 10 include files stdio.h, ..., sys/time.h - found
-- Looking for 12 include files stdio.h, ..., sys/uio.h
-- Looking for 12 include files stdio.h, ..., sys/uio.h - found
-- Looking for 13 include files stdio.h, ..., sys/un.h
-- Looking for 13 include files stdio.h, ..., sys/un.h - found
-- Looking for 14 include files stdio.h, ..., sys/utime.h
-- Looking for 14 include files stdio.h, ..., sys/utime.h - not found
-- Looking for 14 include files stdio.h, ..., alloca.h
-- Looking for 14 include files stdio.h, ..., alloca.h - found
-- Looking for 15 include files stdio.h, ..., arpa/inet.h
-- Looking for 15 include files stdio.h, ..., arpa/inet.h - found
-- Looking for 16 include files stdio.h, ..., arpa/tftp.h
-- Looking for 16 include files stdio.h, ..., arpa/tftp.h - found
-- Looking for 17 include files stdio.h, ..., assert.h
-- Looking for 17 include files stdio.h, ..., assert.h - found
-- Looking for 18 include files stdio.h, ..., crypto.h
-- Looking for 18 include files stdio.h, ..., crypto.h - not found
-- Looking for 18 include files stdio.h, ..., des.h
-- Looking for 18 include files stdio.h, ..., des.h - not found
-- Looking for 18 include files stdio.h, ..., err.h
-- Looking for 18 include files stdio.h, ..., err.h - found
-- Looking for 19 include files stdio.h, ..., errno.h
-- Looking for 19 include files stdio.h, ..., errno.h - found
-- Looking for 20 include files stdio.h, ..., fcntl.h
-- Looking for 20 include files stdio.h, ..., fcntl.h - found
-- Looking for 21 include files stdio.h, ..., idn2.h
-- Looking for 21 include files stdio.h, ..., idn2.h - not found
-- Looking for 21 include files stdio.h, ..., ifaddrs.h
-- Looking for 21 include files stdio.h, ..., ifaddrs.h - found
-- Looking for 22 include files stdio.h, ..., io.h
-- Looking for 22 include files stdio.h, ..., io.h - not found
-- Looking for 22 include files stdio.h, ..., krb.h
-- Looking for 22 include files stdio.h, ..., krb.h - not found
-- Looking for 22 include files stdio.h, ..., libgen.h
-- Looking for 22 include files stdio.h, ..., libgen.h - found
-- Looking for 23 include files stdio.h, ..., limits.h
-- Looking for 23 include files stdio.h, ..., limits.h - found
-- Looking for 24 include files stdio.h, ..., locale.h
-- Looking for 24 include files stdio.h, ..., locale.h - found
-- Looking for 25 include files stdio.h, ..., net/if.h
-- Looking for 25 include files stdio.h, ..., net/if.h - found
-- Looking for 26 include files stdio.h, ..., netdb.h
-- Looking for 26 include files stdio.h, ..., netdb.h - found
-- Looking for 27 include files stdio.h, ..., netinet/in.h
-- Looking for 27 include files stdio.h, ..., netinet/in.h - found
-- Looking for 28 include files stdio.h, ..., netinet/tcp.h
-- Looking for 28 include files stdio.h, ..., netinet/tcp.h - found
-- Looking for 29 include files stdio.h, ..., pem.h
-- Looking for 29 include files stdio.h, ..., pem.h - not found
-- Looking for 29 include files stdio.h, ..., poll.h
-- Looking for 29 include files stdio.h, ..., poll.h - found
-- Looking for 30 include files stdio.h, ..., pwd.h
-- Looking for 30 include files stdio.h, ..., pwd.h - found
-- Looking for 31 include files stdio.h, ..., rsa.h
-- Looking for 31 include files stdio.h, ..., rsa.h - not found
-- Looking for 31 include files stdio.h, ..., setjmp.h
-- Looking for 31 include files stdio.h, ..., setjmp.h - found
-- Looking for 32 include files stdio.h, ..., sgtty.h
-- Looking for 32 include files stdio.h, ..., sgtty.h - found
-- Looking for 33 include files stdio.h, ..., signal.h
-- Looking for 33 include files stdio.h, ..., signal.h - found
-- Looking for 34 include files stdio.h, ..., ssl.h
-- Looking for 34 include files stdio.h, ..., ssl.h - not found
-- Looking for 34 include files stdio.h, ..., stdbool.h
-- Looking for 34 include files stdio.h, ..., stdbool.h - found
-- Looking for 37 include files stdio.h, ..., stdlib.h
-- Looking for 37 include files stdio.h, ..., stdlib.h - found
-- Looking for 38 include files stdio.h, ..., string.h
-- Looking for 38 include files stdio.h, ..., string.h - found
-- Looking for 39 include files stdio.h, ..., strings.h
-- Looking for 39 include files stdio.h, ..., strings.h - found
-- Looking for 40 include files stdio.h, ..., stropts.h
-- Looking for 40 include files stdio.h, ..., stropts.h - found
-- Looking for 41 include files stdio.h, ..., termio.h
-- Looking for 41 include files stdio.h, ..., termio.h - found
-- Looking for 42 include files stdio.h, ..., termios.h
-- Looking for 42 include files stdio.h, ..., termios.h - found
-- Looking for 43 include files stdio.h, ..., time.h
-- Looking for 43 include files stdio.h, ..., time.h - found
-- Looking for 44 include files stdio.h, ..., unistd.h
-- Looking for 44 include files stdio.h, ..., unistd.h - found
-- Looking for 45 include files stdio.h, ..., utime.h
-- Looking for 45 include files stdio.h, ..., utime.h - found
-- Looking for 46 include files stdio.h, ..., x509.h
-- Looking for 46 include files stdio.h, ..., x509.h - not found
-- Looking for 46 include files stdio.h, ..., process.h
-- Looking for 46 include files stdio.h, ..., process.h - not found
-- Looking for 47 include files stdio.h, ..., dlfcn.h
-- Looking for 47 include files stdio.h, ..., dlfcn.h - found
-- Looking for 48 include files stdio.h, ..., malloc.h
-- Looking for 48 include files stdio.h, ..., malloc.h - found
-- Looking for 49 include files stdio.h, ..., memory.h
-- Looking for 49 include files stdio.h, ..., memory.h - found
-- Looking for 50 include files stdio.h, ..., netinet/if_ether.h
-- Looking for 50 include files stdio.h, ..., netinet/if_ether.h - found
-- Looking for 52 include files stdio.h, ..., sockio.h
-- Looking for 52 include files stdio.h, ..., sockio.h - not found
-- Looking for 52 include files stdio.h, ..., sys/utsname.h
-- Looking for 52 include files stdio.h, ..., sys/utsname.h - found
-- Check size of size_t
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_40944" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_40944" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of size_t - failed
-- Check size of ssize_t
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_0c917" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_0c917" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of ssize_t - failed
-- Check size of long long
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_491c0" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_491c0" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of long long - failed
-- Check size of long
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_b7f56" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_b7f56" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of long - failed
-- Check size of short
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_8c4f2" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_8c4f2" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of short - failed
-- Check size of int
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_cfeb3" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_cfeb3" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of int - failed
-- Check size of __int64
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_46263" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_46263" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of __int64 - failed
-- Check size of long double
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_70128" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_70128" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of long double - failed
-- Check size of time_t
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_36bed" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_36bed" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of time_t - failed
-- Looking for basename
-- Looking for basename - found
-- Looking for socket
-- Looking for socket - found
-- Looking for poll
-- Looking for poll - found
-- Looking for select
-- Looking for select - found
-- Looking for strdup
-- Looking for strdup - found
-- Looking for strstr
-- Looking for strstr - found
-- Looking for strtok_r
-- Looking for strtok_r - found
-- Looking for strftime
-- Looking for strftime - found
-- Looking for uname
-- Looking for uname - found
-- Looking for strcasecmp
-- Looking for strcasecmp - found
-- Looking for stricmp
-- Looking for stricmp - not found
-- Looking for strcmpi
-- Looking for strcmpi - not found
-- Looking for strncmpi
-- Looking for strncmpi - not found
-- Looking for alarm
-- Looking for alarm - found
-- Looking for gethostbyaddr
-- Looking for gethostbyaddr - found
-- Looking for gethostbyaddr_r
-- Looking for gethostbyaddr_r - found
-- Looking for gettimeofday
-- Looking for gettimeofday - found
-- Looking for inet_addr
-- Looking for inet_addr - found
-- Looking for inet_ntoa
-- Looking for inet_ntoa - found
-- Looking for inet_ntoa_r
-- Looking for inet_ntoa_r - not found
-- Looking for tcsetattr
-- Looking for tcsetattr - found
-- Looking for tcgetattr
-- Looking for tcgetattr - found
-- Looking for perror
-- Looking for perror - found
-- Looking for closesocket
-- Looking for closesocket - not found
-- Looking for setvbuf
-- Looking for setvbuf - found
-- Looking for sigsetjmp
-- Looking for sigsetjmp - found
-- Looking for getpass_r
-- Looking for getpass_r - not found
-- Looking for strlcat
-- Looking for strlcat - not found
-- Looking for getpwuid
-- Looking for getpwuid - found
-- Looking for geteuid
-- Looking for geteuid - found
-- Looking for utime
-- Looking for utime - found
-- Looking for RAND_status
-- Looking for RAND_status - not found
-- Looking for RAND_screen
-- Looking for RAND_screen - not found
-- Looking for RAND_egd
-- Looking for RAND_egd - not found
-- Looking for gmtime_r
-- Looking for gmtime_r - found
-- Looking for localtime_r
-- Looking for localtime_r - found
-- Looking for gethostbyname
-- Looking for gethostbyname - found
-- Looking for gethostbyname_r
-- Looking for gethostbyname_r - found
-- Looking for signal
-- Looking for signal - found
-- Looking for SIGALRM
-- Looking for SIGALRM - found
-- Looking for strtoll
-- Looking for strtoll - found
-- Looking for _strtoi64
-- Looking for _strtoi64 - not found
-- Looking for strerror_r
-- Looking for strerror_r - found
-- Looking for siginterrupt
-- Looking for siginterrupt - found
-- Looking for fork
-- Looking for fork - found
-- Looking for getaddrinfo
-- Looking for getaddrinfo - found
-- Looking for freeaddrinfo
-- Looking for freeaddrinfo - found
-- Looking for freeifaddrs
-- Looking for freeifaddrs - found
-- Looking for pipe
-- Looking for pipe - found
-- Looking for ftruncate
-- Looking for ftruncate - found
-- Looking for getprotobyname
-- Looking for getprotobyname - found
-- Looking for getrlimit
-- Looking for getrlimit - found
-- Looking for setlocale
-- Looking for setlocale - found
-- Looking for setrlimit
-- Looking for setrlimit - found
-- Looking for fcntl
-- Looking for fcntl - found
-- Looking for ioctl
-- Looking for ioctl - found
-- Looking for setsockopt
-- Looking for setsockopt - found
-- Looking for inet_pton
-- Looking for inet_pton - found
-- Looking for sigaction
-- Looking for sigaction - found
-- Performing Curl Test HAVE_FCNTL_O_NONBLOCK
-- Performing Curl Test HAVE_FCNTL_O_NONBLOCK - Success
-- Performing Curl Test HAVE_IOCTLSOCKET
-- Performing Curl Test HAVE_IOCTLSOCKET - Failed
-- Performing Curl Test HAVE_IOCTLSOCKET_CAMEL
-- Performing Curl Test HAVE_IOCTLSOCKET_CAMEL - Failed
-- Performing Curl Test HAVE_IOCTLSOCKET_CAMEL_FIONBIO
-- Performing Curl Test HAVE_IOCTLSOCKET_CAMEL_FIONBIO - Failed
-- Performing Curl Test HAVE_IOCTLSOCKET_FIONBIO
-- Performing Curl Test HAVE_IOCTLSOCKET_FIONBIO - Failed
-- Performing Curl Test HAVE_IOCTL_FIONBIO
-- Performing Curl Test HAVE_IOCTL_FIONBIO - Success
-- Performing Curl Test HAVE_IOCTL_SIOCGIFADDR
-- Performing Curl Test HAVE_IOCTL_SIOCGIFADDR - Success
-- Performing Curl Test HAVE_SETSOCKOPT_SO_NONBLOCK
-- Performing Curl Test HAVE_SETSOCKOPT_SO_NONBLOCK - Failed
-- Performing Curl Test TIME_WITH_SYS_TIME
-- Performing Curl Test TIME_WITH_SYS_TIME - Success
-- Performing Curl Test HAVE_O_NONBLOCK
-- Performing Curl Test HAVE_O_NONBLOCK - Failed
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_5
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_5 - Failed
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_7
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_7 - Failed
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_8
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_8 - Success
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_5_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_5_REENTRANT - Failed
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_7_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_7_REENTRANT - Failed
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_8_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYADDR_R_8_REENTRANT - Success
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_3
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_3 - Failed
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_5
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_5 - Failed
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_6
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_6 - Success
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_3_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_3_REENTRANT - Failed
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_5_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_5_REENTRANT - Failed
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_6_REENTRANT
-- Performing Curl Test HAVE_GETHOSTBYNAME_R_6_REENTRANT - Success
-- Performing Curl Test HAVE_SOCKLEN_T
-- Performing Curl Test HAVE_SOCKLEN_T - Success
-- Performing Curl Test HAVE_IN_ADDR_T
-- Performing Curl Test HAVE_IN_ADDR_T - Success
-- Performing Curl Test HAVE_BOOL_T
-- Performing Curl Test HAVE_BOOL_T - Success
-- Performing Curl Test STDC_HEADERS
-- Performing Curl Test STDC_HEADERS - Success
-- Performing Curl Test RETSIGTYPE_TEST
-- Performing Curl Test RETSIGTYPE_TEST - Success
-- Performing Curl Test HAVE_INET_NTOA_R_DECL
-- Performing Curl Test HAVE_INET_NTOA_R_DECL - Failed
-- Performing Curl Test HAVE_INET_NTOA_R_DECL_REENTRANT
-- Performing Curl Test HAVE_INET_NTOA_R_DECL_REENTRANT - Failed
-- Performing Curl Test HAVE_FILE_OFFSET_BITS
-- Performing Curl Test HAVE_FILE_OFFSET_BITS - Success
-- Check size of off_t
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_ac7c7" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_ac7c7" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of off_t - failed
-- Performing Curl Test HAVE_GLIBC_STRERROR_R
-- Performing Curl Test HAVE_GLIBC_STRERROR_R - Failed
-- Performing Curl Test HAVE_POSIX_STRERROR_R
-- Performing Curl Test HAVE_POSIX_STRERROR_R - Success
-- Check size of socklen_t
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
OPENSSL_CRYPTO_LIBRARY
linked by target "cmTC_a55e3" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp
OPENSSL_SSL_LIBRARY
linked by target "cmTC_a55e3" in directory /home/anthony/citra/build/CMakeFiles/CMakeTmp

CMake Error: Internal CMake error, TryCompile configure of cmake failed
-- Check size of socklen_t - failed
CMake Error at externals/cpr/opt/curl/CMakeLists.txt:993 (message):
Check for sizeof socklen_t failed, see CMakeFiles/CMakerror.log


-- Configuring incomplete, errors occurred!
See also "/home/anthony/citra/build/CMakeFiles/CMakeOutput.log".
See also "/home/anthony/citra/build/CMakeFiles/CMakeError.log".

Usually, the first error is what you go after. In your case, you seem to be missing essentials, or else have them hidden from your compile project.

Stdio.h is a pretty essential GNU file, so I reckon it's includes are essential also. Have you kernel headers and gcc installed? I have 5 stdio.h files in /usr/include, and they are all different. Time for some reading of the docs.

You can probably get around this with compile options

When I use locate stdio.h I'm finding it so I don't know why it's not working:

anthony@anthony-Aspire-ES1-411:~$ locate stdio.h
/usr/include/stdio.h
/usr/include/boost/iostreams/filter/stdio.hpp
/usr/include/c++/5/tr1/stdio.h
/usr/include/c++/6/tr1/stdio.h
/usr/include/c++/7/tr1/stdio.h
/usr/include/c++/v1/stdio.h
/usr/include/glib-2.0/glib/gstdio.h
/usr/include/x86_64-linux-gnu/bits/stdio.h
/usr/lib/x86_64-linux-gnu/perl/5.24.1/CORE/nostdio.h

What libraries/packages would you suggest I try to install?

Why not grep the Makefile for stdio.h?

Usually, they have a /root of /usr/include, so

# include stdio.h

actually means 'include /usr/include/stdio.h.' It might be looking for a particular one that isn't there.