Hello, @eskimo , I am a colleague of @kimjitae . Let me explain what happens. Sometimes, clang cannot process -o option and it gives the error, 'cannot specify -o when generating multiple output files'. However, when I remove the part after -o, it compiles the file alright. It seems that clang cannot process -o option properly in some circumstances, though I couldn't figure out why yet. (paths are edited) /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -x c -ivfsstatcache /Users/me/Library/Developer/Xcode/DerivedData/SDKStatCaches.noindex/iphonesimulator17.4-21E210-aa93b11c43e2d16681ac3fa171344f4f.sdkstatcache -fmessage-length=0 -fdiagnostics-show-note-include-stack -fmacro-backtrace-limit=0 -fno-color-diagnostics -Wno-trigraphs -Wno-missing-field-initializers -Wno-missing-prototypes -Werror=return-type -Wdocumentation -Wunreachable-code -Werror=deprecated-objc-isa-usage -Werror=objc-root-class -Wno-missing-braces -Wparentheses -Wswitch -Wunused-function -Wno-unused-label -Wno-unused-parameter -Wunused-variable -Wunused-value -Wempty-body -Wuninitialized -Wconditional-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants -Wno-conversion -Wconstant-conversion -Wint-conversion -Wbool-conversion -Wenum-conversion -Wno-float-conversion -Wnon-literal-null-conversion -Wobjc-literal-conversion -Wshorten-64-to-32 -Wpointer-sign -Wno-newline-eof -Wno-implicit-fallthrough -fstrict-aliasing -Wdeprecated-declarations -Wno-sign-conversion -Winfinite-recursion -Wcomma -Wblock-capture-autoreleasing -Wstrict-prototypes -Wno-semicolon-before-method-body -Wunguarded-availability -Wno-ambiguous-macro @/Users/me/Library/Developer/Xcode/DerivedData/project-cexwczazumtpztgpgzvhxojjgqab/Build/Intermediates.noindex/project.build/Release\ Device-iphonesimulator/NAVI\ 3.0.build/Objects-normal-asan/x86_64/7187679823f38a2a940e0043cdf9d637-common-args.resp -include /Users/me/navi3/navi-ios-3.0/NAVI3.0_WEU/NAVIPrefix.h -MMD -MT dependencies -MF /Users/me/Library/Developer/Xcode/DerivedData/project-cexwczazumtpztgpgzvhxojjgqab/Build/Intermediates.noindex/project.build/Release\ Device-iphonesimulator/NAVI\ 3.0.build/Objects-normal-asan/x86_64/zip.d --serialize-diagnostics /Users/me/Library/Developer/Xcode/DerivedData/project-cexwczazumtpztgpgzvhxojjgqab/Build/Intermediates.noindex/project.build/Release\ Device-iphonesimulator/NAVI\ 3.0.build/Objects-normal-asan/x86_64/zip.dia -c /Users/me/navi3/app-engine-3.0/Libraries/Util/ZipArchive/minizip/zip.c -o /Users/me/Library/Developer/Xcode/DerivedData/project-cexwczazumtpztgpgzvhxojjgqab/Build/Intermediates.noindex/project.build/Release\ Device-iphonesimulator/NAVI\ 3.0.build/Objects-normal-asan/x86_64/zip.o