How do I print a list of "Build Settings" in Xcode project?

UPDATE: This list is getting a little out dated (it was generated with Xcode 4.1). You should run the command suggested by dunedin15.

dunedin15's answer can give inaccurate results for some edge-cases, such as when debugging build settings of a static lib for an Archive build, see Slipp D. Thompson's answer for a more robust output.

Original Answer

Variable                                  ExamplePATH                                      "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"LANG                                      en_US.US-ASCIIIPHONEOS_DEPLOYMENT_TARGET                4.1ACTION                                    buildAD_HOC_CODE_SIGNING_ALLOWED               NOALTERNATE_GROUP                           staffALTERNATE_MODE                            u+w,go-w,a+rXALTERNATE_OWNER                           usernameALWAYS_SEARCH_USER_PATHS                  YESAPPLE_INTERNAL_DEVELOPER_DIR              /AppleInternal/DeveloperAPPLE_INTERNAL_DIR                        /AppleInternalAPPLE_INTERNAL_DOCUMENTATION_DIR          /AppleInternal/DocumentationAPPLE_INTERNAL_LIBRARY_DIR                /AppleInternal/LibraryAPPLE_INTERNAL_TOOLS                      /AppleInternal/Developer/ToolsAPPLY_RULES_IN_COPY_FILES                 NOARCHS                                     "armv6 armv7"ARCHS_STANDARD_32_64_BIT                  "armv6 armv7"ARCHS_STANDARD_32_BIT                     "armv6 armv7"ARCHS_UNIVERSAL_IPHONE_OS                 armv7AVAILABLE_PLATFORMS                       "iphonesimulator macosx iphoneos"BUILD_COMPONENTS                          "headers build"BUILD_DIR                                 "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath"BUILD_ROOT                                "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath"BUILD_STYLE                    BUILD_VARIANTS                             normalBUILT_PRODUCTS_DIR                         "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos"CACHE_ROOT                                 /var/folders/2x/rvb2r9s16mq6r318zxvn0lk80000gn/C/com.apple.Xcode.501CCHROOT                                    /var/folders/2x/rvb2r9s16mq6r318zxvn0lk80000gn/C/com.apple.Xcode.501CHMOD                                      /bin/chmodCHOWN                                      /usr/sbin/chownCLASS_FILE_DIR                             "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/JavaClasses"CLEAN_PRECOMPS                             YESCLONE_HEADERS                              NOCODESIGNING_FOLDER_PATH                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/InstallationBuildProductsLocation/Applications/project.app"CODE_SIGNING_ALLOWED                       YESCODE_SIGNING_REQUIRED                      YESCODE_SIGN_CONTEXT_CLASS                    XCiPhoneOSCodeSignContextCODE_SIGN_IDENTITY                         "iPhone Distribution"COMBINE_HIDPI_IMAGES                       NOCOMPOSITE_SDK_DIRS                         /var/folders/2x/rvb2r9s16mq6r318zxvn0lk80000gn/C/com.apple.Xcode.501/CompositeSDKsCOMPRESS_PNG_FILES                         YESCONFIGURATION                              DistributionCONFIGURATION_BUILD_DIR                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos"CONFIGURATION_TEMP_DIR                     "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos"CONTENTS_FOLDER_PATH                       project.app/ContentsCOPYING_PRESERVES_HFS_DATA                 NOCOPY_PHASE_STRIP                           YESCOPY_RESOURCES_FROM_STATIC_FRAMEWORKS      YESCP                                         /bin/cpCURRENT_ARCH                               armv7CURRENT_VARIANT                            normalDEAD_CODE_STRIPPING                        YESDEBUGGING_SYMBOLS                          YESDEBUG_INFORMATION_FORMAT                   dwarf-with-dsymDEPLOYMENT_LOCATION                        YESDEPLOYMENT_POSTPROCESSING                  YESDERIVED_FILES_DIR                          "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/DerivedSources"DERIVED_FILE_DIR                           "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/DerivedSources"DERIVED_SOURCES_DIR                        "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/DerivedSources"DEVELOPER_APPLICATIONS_DIR                 /Developer/ApplicationsDEVELOPER_BIN_DIR                          /Developer/usr/binDEVELOPER_DIR                              /DeveloperDEVELOPER_FRAMEWORKS_DIR                   /Developer/Library/FrameworksDEVELOPER_FRAMEWORKS_DIR_QUOTED            "\"/Developer/Library/Frameworks\""DEVELOPER_LIBRARY_DIR                      /Developer/LibraryDEVELOPER_SDK_DIR                          /Developer/SDKsDEVELOPER_TOOLS_DIR                        /Developer/ToolsDEVELOPER_USR_DIR                          /Developer/usrDEVELOPMENT_LANGUAGE                       EnglishDOCUMENTATION_FOLDER_PATH                  project.app/English.lproj/DocumentationDO_HEADER_SCANNING_IN_JAM                  NODSTROOT                                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/InstallationBuildProductsLocation"DWARF_DSYM_FILE_NAME                       project.app.dSYMDWARF_DSYM_FILE_SHOULD_ACCOMPANY_PRODUCT   NODWARF_DSYM_FOLDER_PATH                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos"EFFECTIVE_PLATFORM_NAME                    -iphoneosEMBEDDED_PROFILE_NAME                      embedded.mobileprovisionENABLE_HEADER_DEPENDENCIES                 YESENABLE_OPENMP_SUPPORT                      NOENTITLEMENTS_ALLOWED                       YESENTITLEMENTS_REQUIRED                      YESEXCLUDED_INSTALLSRC_SUBDIRECTORY_PATTERNS  ".svn CVS"EXECUTABLES_FOLDER_PATH                    project.app/ExecutablesEXECUTABLE_FOLDER_PATH                     project.appEXECUTABLE_NAME                            projectEXECUTABLE_PATH                            project.app/projectFILE_LIST                                  "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/Objects/LinkFileList"FIXED_FILES_DIR                            "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/FixedFiles"FRAMEWORKS_FOLDER_PATH                     project.app/FrameworksFRAMEWORK_FLAG_PREFIX                      -frameworkFRAMEWORK_SEARCH_PATHS                     "\"/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos\" "FRAMEWORK_VERSION                          AFULL_PRODUCT_NAME                          project.appGCC3_VERSION                               3.3GCC_C_LANGUAGE_STANDARD                    gnu99GCC_INLINES_ARE_PRIVATE_EXTERN             YESGCC_PFE_FILE_C_DIALECTS                    "c objective-c c++ objective-c++"GCC_PRECOMPILE_PREFIX_HEADER               YESGCC_PREFIX_HEADER                          project/Prefix.pchGCC_PREPROCESSOR_DEFINITIONS               "NDEBUG DISTRIBUTION_BUILD=1 KK_TARGET=0x000F0"GCC_SYMBOLS_PRIVATE_EXTERN                 YESGCC_THUMB_SUPPORT                          YESGCC_TREAT_WARNINGS_AS_ERRORS               NOGCC_VERSION                                com.apple.compilers.llvm.clang.1_0GCC_VERSION_IDENTIFIER                     com_apple_compilers_llvm_clang_1_0GCC_WARN_ABOUT_RETURN_TYPE                 YESGCC_WARN_UNUSED_FUNCTION                   YESGCC_WARN_UNUSED_VARIABLE                   YESGENERATE_MASTER_OBJECT_FILE                NOGENERATE_PKGINFO_FILE                      YESGENERATE_PROFILING_CODE                    NOGID                                        20GROUP                                      staffINPUT_FILE_BASE             DefaultINPUT_FILE_DIR              "/Volumes/Development/Project Game/Project-v1/images"INPUT_FILE_NAME             Default.pngINPUT_FILE_PATH             "/Volumes/Development/Project Game/Project-v1/images/Default.png"SCRIPT_INPUT_FILE           "/Volumes/Development/Project Game/Project-v1/images/Default.png"SCRIPT_OUTPUT_FILE_0        "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/DerivedSources/Default.png"EXCLUDED_RECURSIVE_SEARCH_PATH_SUBDIRECTORIES              "*.nib *.lproj *.framework *.gch (*) CVS .svn .git *.xcodeproj *.xcode *.pbproj *.pbxproj"HEADERMAP_INCLUDES_FLAT_ENTRIES_FOR_TARGET_BEING_BUILT     YESHEADERMAP_INCLUDES_FRAMEWORK_ENTRIES_FOR_ALL_PRODUCT_TYPES YESHEADERMAP_INCLUDES_NONPUBLIC_NONPRIVATE_HEADERS            YESHEADERMAP_INCLUDES_PROJECT_HEADERS                         YESHEADER_SEARCH_PATHS                  "\"/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos/include\" "ICONV                                /usr/bin/iconvINFOPLIST_EXPAND_BUILD_SETTINGS      YESINFOPLIST_FILE                       project/Resources/Info.plistINFOPLIST_OUTPUT_FORMAT              binaryINFOPLIST_PATH                       project.app/Info.plistINFOPLIST_PREPROCESS                 NOINFOSTRINGS_PATH                     project.app/English.lproj/InfoPlist.stringsINPUT_FILE_REGION_PATH_COMPONENT                    INPUT_FILE_SUFFIX                    .pngINSTALL_DIR                          "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/InstallationBuildProductsLocation/Applications"INSTALL_GROUP                        staffINSTALL_MODE_FLAG                    u+w,go-w,a+rXINSTALL_OWNER                        usernameINSTALL_PATH                         /ApplicationsINSTALL_ROOT                         "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/InstallationBuildProductsLocation"JAVAC_DEFAULT_FLAGS                  "-J-Xms64m -J-XX:NewSize=4M -J-Dfile.encoding=UTF8"JAVA_APP_STUB                        /System/Library/Frameworks/JavaVM.framework/Resources/MacOS/JavaApplicationStubJAVA_ARCHIVE_CLASSES                 YESJAVA_ARCHIVE_TYPE                    JARJAVA_COMPILER                        /usr/bin/javacJAVA_FOLDER_PATH                     project.app/JavaJAVA_FRAMEWORK_RESOURCES_DIRS        ResourcesJAVA_JAR_FLAGS                       cvJAVA_SOURCE_SUBDIR                   .JAVA_USE_DEPENDENCIES                YESJAVA_ZIP_FLAGS                       -urgJIKES_DEFAULT_FLAGS                  "+E +OLDCSO"KEEP_PRIVATE_EXTERNS                 NOLD_GENERATE_MAP_FILE                 NOLD_MAP_FILE_PATH                     "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/project-LinkMap-normal-armv7.txt"LD_NO_PIE                            NOLD_OPENMP_FLAGS                      -fopenmpLEGACY_DEVELOPER_DIR                 /Developer/Library/Xcode/PrivatePlugIns/Xcode3Core.ideplugin/Contents/SharedSupport/DeveloperLEX                                  /Developer/usr/bin/lexLIBRARY_FLAG_NOSPACE                 YESLIBRARY_FLAG_PREFIX                  -lLIBRARY_SEARCH_PATHS                 "\"/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos\"  \"/Volumes/Development/Project Game/Project-v1/FlurryLib\""LINKER_DISPLAYS_MANGLED_NAMES        NOLINK_FILE_LIST_normal_armv6          "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/Objects-normal/armv6/project.LinkFileList"LINK_FILE_LIST_normal_armv7          "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/Objects-normal/armv7/project.LinkFileList"LINK_WITH_STANDARD_LIBRARIES         YESLOCALIZED_RESOURCES_FOLDER_PATH      project.app/English.lprojLOCAL_ADMIN_APPS_DIR                 /Applications/UtilitiesLOCAL_APPS_DIR                       /ApplicationsLOCAL_DEVELOPER_DIR                  /Library/DeveloperLOCAL_LIBRARY_DIR                    /LibraryMACH_O_TYPE                          mh_executeMAC_OS_X_PRODUCT_BUILD_VERSION       11A511MAC_OS_X_VERSION_ACTUAL              1070MAC_OS_X_VERSION_MAJOR               1070MAC_OS_X_VERSION_MINOR               0700NATIVE_ARCH                          armv6NATIVE_ARCH_32_BIT                   i386NATIVE_ARCH_64_BIT                   x86_64NATIVE_ARCH_ACTUAL                   x86_64NO_COMMON                            YESOBJECT_FILE_DIR                      "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/Objects"OBJECT_FILE_DIR_normal               "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/Objects-normal"OBJROOT                              "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath"ONLY_ACTIVE_ARCH                     NOOPTIMIZATION_LEVEL                   0OS                                   MACOSOSAC                                 /usr/bin/osacompileOTHER_CFLAGS                         -DNS_BLOCK_ASSERTIONS=1OTHER_CPLUSPLUSFLAGS                 -DNS_BLOCK_ASSERTIONS=1OTHER_INPUT_FILE_FLAGS                    OTHER_LDFLAGS                        -lzPACKAGE_TYPE                         com.apple.package-type.wrapper.applicationPASCAL_STRINGS                       YESPATH_PREFIXES_EXCLUDED_FROM_HEADER_DEPENDENCIES  "/usr/include /usr/local/include /System/Library/Frameworks /System/Library/PrivateFrameworks /Developer/Headers /Developer/SDKs /Developer/Platforms"PBDEVELOPMENTPLIST_PATH              project.app/pbdevelopment.plistPFE_FILE_C_DIALECTS                  "c objective-c c++ objective-c++"PKGINFO_FILE_PATH                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/PkgInfo"PKGINFO_PATH                         project.app/PkgInfoPLATFORM_DEVELOPER_APPLICATIONS_DIR  /Developer/Platforms/iPhoneOS.platform/Developer/ApplicationsPLATFORM_DEVELOPER_BIN_DIR           /Developer/Platforms/iPhoneOS.platform/Developer/usr/binPLATFORM_DEVELOPER_LIBRARY_DIR       /Developer/Library/Xcode/PrivatePlugIns/Xcode3Core.ideplugin/Contents/SharedSupport/Developer/LibraryPLATFORM_DEVELOPER_SDK_DIR           /Developer/Platforms/iPhoneOS.platform/Developer/SDKsPLATFORM_DEVELOPER_TOOLS_DIR         /Developer/Platforms/iPhoneOS.platform/Developer/ToolsPLATFORM_DEVELOPER_USR_DIR           /Developer/Platforms/iPhoneOS.platform/Developer/usrPLATFORM_DIR                         /Developer/Platforms/iPhoneOS.platformPLATFORM_NAME                        iphoneosPLATFORM_PREFERRED_ARCH              i386PLATFORM_PRODUCT_BUILD_VERSION       8H7PLIST_FILE_OUTPUT_FORMAT             binaryPLUGINS_FOLDER_PATH                  project.app/PlugInsPRECOMPS_INCLUDE_HEADERS_FROM_BUILT_PRODUCTS_DIR                    YESPRECOMP_DESTINATION_DIR              "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/PrefixHeaders"PRESERVE_DEAD_CODE_INITS_AND_TERMS   NOPRIVATE_HEADERS_FOLDER_PATH          project.app/PrivateHeadersPRODUCT_NAME                         projectPRODUCT_SETTINGS_PATH                "/Volumes/Development/Project Game/Project-v1/project/Resources/Info.plist"PRODUCT_TYPE                         com.apple.product-type.applicationPROFILING_CODE                       NOPROJECT                              projectPROJECT_DERIVED_FILE_DIR             "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/DerivedSources"PROJECT_DIR                          "/Volumes/Development/Project Game/Project-v1"PROJECT_FILE_PATH                    "/Volumes/Development/Project Game/Project-v1/project.xcodeproj"PROJECT_NAME                         projectPROJECT_TEMP_DIR                     "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build"PROVISIONING_PROFILE_REQUIRED        YESPUBLIC_HEADERS_FOLDER_PATH           project.app/HeadersRECURSIVE_SEARCH_PATHS_FOLLOW_SYMLINKS   YESREMOVE_CVS_FROM_RESOURCES            YESREMOVE_GIT_FROM_RESOURCES            YESREMOVE_SVN_FROM_RESOURCES            YESRESOURCE_RULES_REQUIRED              YESREZ_COLLECTOR_DIR                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/ResourceManagerResources"REZ_OBJECTS_DIR                      "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/ResourceManagerResources/Objects"REZ_SEARCH_PATHS                     "\"/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos\" "RUN_CLANG_STATIC_ANALYZER            NOSCAN_ALL_SOURCE_FILES_FOR_INCLUDES   NOSCRIPTS_FOLDER_PATH                  project.app/ScriptsSCRIPT_INPUT_FILE                    "/Volumes/Development/Project Game/Project-v1/fonts/helvetica-black-hd.png"SCRIPT_OUTPUT_FILE_0                 "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build/DerivedSources/helvetica-black-hd.png"SCRIPT_OUTPUT_FILE_COUNT             1SDKROOT                              /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdkSDK_DIR                              /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdkSDK_NAME                             iphoneos4.3SDK_PRODUCT_BUILD_VERSION            8H7SED                                  /usr/bin/sedSEPARATE_STRIP                       NOSEPARATE_SYMBOL_EDIT                 NOSET_DIR_MODE_OWNER_GROUP            YESSET_FILE_MODE_OWNER_GROUP           NOSHALLOW_BUNDLE                      YESSHARED_DERIVED_FILE_DIR             "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath/Distribution-iphoneos/DerivedSources"SHARED_FRAMEWORKS_FOLDER_PATH       project.app/SharedFrameworksSHARED_PRECOMPS_DIR                 /Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/Build/PrecompiledHeadersSHARED_SUPPORT_FOLDER_PATH          project.app/SharedSupportSKIP_INSTALL                        NOSOURCE_ROOT                         "/Volumes/Development/Project Game/Project-v1"SRCROOT                             "/Volumes/Development/Project Game/Project-v1"STRINGS_FILE_OUTPUT_ENCODING        binarySTRIP_INSTALLED_PRODUCT             YESSTRIP_STYLE                         allSUPPORTED_DEVICE_FAMILIES           1,2SUPPORTED_PLATFORMS                 "iphonesimulator iphoneos"SYMROOT                             "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/BuildProductsPath"SYSTEM_ADMIN_APPS_DIR               /Applications/UtilitiesSYSTEM_APPS_DIR                     /ApplicationsSYSTEM_CORE_SERVICES_DIR            /System/Library/CoreServicesSYSTEM_DEMOS_DIR                    /Applications/ExtrasSYSTEM_DEVELOPER_APPS_DIR           /Developer/ApplicationsSYSTEM_DEVELOPER_BIN_DIR            /Developer/usr/binSYSTEM_DEVELOPER_DEMOS_DIR          "/Developer/Applications/Utilities/Built Examples"SYSTEM_DEVELOPER_DIR                /DeveloperSYSTEM_DEVELOPER_DOC_DIR            "/Developer/ADC Reference Library"SYSTEM_DEVELOPER_GRAPHICS_TOOLS_DIR "/Developer/Applications/Graphics Tools"SYSTEM_DEVELOPER_JAVA_TOOLS_DIR     "/Developer/Applications/Java Tools"SYSTEM_DEVELOPER_PERFORMANCE_TOOLS_DIR   "/Developer/Applications/Performance Tools"SYSTEM_DEVELOPER_RELEASENOTES_DIR   "/Developer/ADC Reference Library/releasenotes"SYSTEM_DEVELOPER_TOOLS              /Developer/ToolsSYSTEM_DEVELOPER_TOOLS_DOC_DIR      "/Developer/ADC Reference Library/documentation/DeveloperTools"SYSTEM_DEVELOPER_TOOLS_RELEASENOTES_DIR   "/Developer/ADC Reference Library/releasenotes/DeveloperTools"SYSTEM_DEVELOPER_USR_DIR            /Developer/usrSYSTEM_DEVELOPER_UTILITIES_DIR      /Developer/Applications/UtilitiesSYSTEM_DOCUMENTATION_DIR            /Library/DocumentationSYSTEM_LIBRARY_DIR                  /System/LibraryTARGETED_DEVICE_FAMILY              1TARGETNAME                          ProjectTARGET_BUILD_DIR                    "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/InstallationBuildProductsLocation/Applications"TARGET_NAME                         ProjectTARGET_TEMP_DIR                     "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build"TEMP_DIR                            "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build"TEMP_FILES_DIR                      "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build"TEMP_FILE_DIR                       "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath/project.build/Distribution-iphoneos/Project.build"TEMP_ROOT                           "/Users/username/Library/Developer/Xcode/DerivedData/project-dxdgjvgsvvbhowgjqouevhmvgxgf/ArchiveIntermediates/Project Distribution/IntermediateBuildFilesPath"TEST_AFTER_BUILD                    NOUID                                 501UNLOCALIZED_RESOURCES_FOLDER_PATH   project.app    UNSTRIPPED_PRODUCT           NOUSER                         usernameUSER_APPS_DIR                /Users/username/ApplicationsUSER_HEADER_SEARCH_PATHS     project/libsUSER_LIBRARY_DIR             /Users/username/LibraryUSE_DYNAMIC_NO_PIC           YESUSE_HEADERMAP                YESUSE_HEADER_SYMLINKS          NOVALIDATE_PRODUCT             YESVALID_ARCHS                  "armv6 armv7"VERBOSE_PBXCP                NOVERSIONPLIST_PATH            project.app/version.plistVERSION_INFO_BUILDER         usernameVERSION_INFO_FILE            project_vers.cVERSION_INFO_STRING          "\"@(#)PROGRAM:project  PROJECT:project-\""WRAPPER_EXTENSION            appWRAPPER_NAME                 project.appWRAPPER_SUFFIX               .appXCODE_APP_SUPPORT_DIR        /Developer/Library/XcodeXCODE_PRODUCT_BUILD_VERSION  4B110XCODE_VERSION_ACTUAL         0410XCODE_VERSION_MAJOR          0400XCODE_VERSION_MINOR          0410YACC                        /Developer/usr/bin/yacc

You can also get this information from the command line using the xcodebuild command with the -showBuildSettings switch:

$ xcodebuild -project myProj.xcodeproj -target "myTarg" -showBuildSettings

This will dump a list like the one shown above to the standard output.

Although @dunedin15's fantastic answer has served me well on a number of occasions, it can give inaccurate results for some edge-cases, such as when debugging build settings of a static lib for an Archive build.

As an alternative, a Run Script Build Phase can be easily added to any target to “Log Build Settings” when it's built:

To add, (with the target in question selected) under the Build Phases tab-section click the little ➕ button a dozen-or-so pixels up-left-ward from the Target Dependencies section, and set the shell to /bin/bash and the command to export.  You'll also probably want to drag the phase upwards so that it happens just after Target Dependencies and before Copy Headers or Compile Sources.  Renaming the phase from “Run Script” to “Log Build Settings” isn't a bad idea.

The result is this incredibly helpful listing of current environment variables used for building: