$ make check
  CC       json.o
In file included from json.c:24:
json.h:66: warning: declaration does not declare anything
json.c: In function ‘json_delete’:
json.c:414: error: ‘JsonNode’ has no member named ‘string_’
json.c:420: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘json_first_child’:
json.c:482: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘json_mkbool’:
json.c:503: error: ‘JsonNode’ has no member named ‘bool_’
json.c: In function ‘mkstring’:
json.c:510: error: ‘JsonNode’ has no member named ‘string_’
json.c: In function ‘json_mknumber’:
json.c:522: error: ‘JsonNode’ has no member named ‘number_’
json.c: In function ‘append_node’:
json.c:539: error: ‘JsonNode’ has no member named ‘children’
json.c:542: error: ‘JsonNode’ has no member named ‘children’
json.c:543: error: ‘JsonNode’ has no member named ‘children’
json.c:545: error: ‘JsonNode’ has no member named ‘children’
json.c:546: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘prepend_node’:
json.c:553: error: ‘JsonNode’ has no member named ‘children’
json.c:555: error: ‘JsonNode’ has no member named ‘children’
json.c:556: error: ‘JsonNode’ has no member named ‘children’
json.c:558: error: ‘JsonNode’ has no member named ‘children’
json.c:559: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘json_remove_from_parent’:
json.c:609: error: ‘JsonNode’ has no member named ‘children’
json.c:613: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘emit_value’:
json.c:982: error: ‘JsonNode’ has no member named ‘bool_’
json.c:985: error: ‘JsonNode’ has no member named ‘string_’
json.c:988: error: ‘JsonNode’ has no member named ‘number_’
json.c: In function ‘emit_value_indented’:
json.c:1009: error: ‘JsonNode’ has no member named ‘bool_’
json.c:1012: error: ‘JsonNode’ has no member named ‘string_’
json.c:1015: error: ‘JsonNode’ has no member named ‘number_’
json.c: In function ‘emit_array_indented’:
json.c:1043: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘emit_object_indented’:
json.c:1082: error: ‘JsonNode’ has no member named ‘children’
json.c: In function ‘json_check’:
json.c:1328: error: ‘JsonNode’ has no member named ‘bool_’
json.c:1328: error: ‘JsonNode’ has no member named ‘bool_’
json.c:1331: error: ‘JsonNode’ has no member named ‘string_’
json.c:1333: error: ‘JsonNode’ has no member named ‘string_’
json.c:1336: error: ‘JsonNode’ has no member named ‘children’
json.c:1337: error: ‘JsonNode’ has no member named ‘children’
make: *** [json.o] Error 1

$ ./configure
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking how to run the C preprocessor... gcc -E
checking for grep that handles long lines and -e... /bin/grep
checking for egrep... /bin/grep -E
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking minix/config.h usability... no
checking minix/config.h presence... no
checking for minix/config.h... no
checking whether it is safe to define __EXTENSIONS__... yes
checking stddef.h usability... yes
checking stddef.h presence... yes
checking for stddef.h... yes
checking for stdint.h... (cached) yes
checking for stdlib.h... (cached) yes
checking for string.h... (cached) yes
checking for stdlib.h... (cached) yes
checking for GNU libc compatible malloc... yes
checking for stdlib.h... (cached) yes
checking for GNU libc compatible realloc... yes
checking for working strtod... yes
checking for strchr... yes
checking for strrchr... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking for style of include used by make... GNU
checking whether make supports nested variables... yes
checking dependency style of gcc... gcc3
checking whether make supports nested variables... (cached) yes
checking for pandoc... no
configure: WARNING: pandoc not found, man pages rebuild will not be possible
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: executing depfiles commands

$ gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.4.7 20120313 (Red Hat 4.4.7-16) (GCC)