# How to solve Following "multiple uses of -o are not allowed" Error ??

**URL:** <https://discourse.cmake.org/t/how-to-solve-following-multiple-uses-of-o-are-not-allowed-error/6220>\
**Category:** Code\
**Tags:** os:windows\
**Created:** [August 5, 2022, 6:40am UTC](https://discourse.cmake.org/t/how-to-solve-following-multiple-uses-of-o-are-not-allowed-error/6220 "2022-08-05T06:40:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![vasantharaj](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/v/bcef8e/32.png) [@vasantharaj](https://discourse.cmake.org/u/vasantharaj)\
**Post date:** [August 5, 2022, 6:40am UTC](https://discourse.cmake.org/t/how-to-solve-following-multiple-uses-of-o-are-not-allowed-error/6220/1 "2022-08-05T06:40:50Z")

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unable generate .elf file using command **-output=${project name}.elf** it showing below given Error.

cctc E204: multiple uses of -o are not allowed  
Compiler: Tasking

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**Author:** ![jtxa](https://discourse.cmake.org/user_avatar/discourse.cmake.org/jtxa/32/1535_2.png) [@jtxa](https://discourse.cmake.org/u/jtxa)\
**Post date:** [August 6, 2022, 11:15pm UTC](https://discourse.cmake.org/t/how-to-solve-following-multiple-uses-of-o-are-not-allowed-error/6220/2 "2022-08-06T23:15:27Z")

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The linker argument list for an `add_executable` already contains the output file (`-o` or `-output`) based on your target name.  
You cannot add this linker argument yourself.

If you need a different filename you can control it via the [OUTPUT\_NAME](https://cmake.org/cmake/help/latest/prop_tgt/OUTPUT_NAME.html#prop_tgt:OUTPUT_NAME) property.

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**Author:** ![go2sh](https://discourse.cmake.org/user_avatar/discourse.cmake.org/go2sh/32/2606_2.png) [@go2sh](https://discourse.cmake.org/u/go2sh)\
**Post date:** [September 14, 2022, 10:53pm UTC](https://discourse.cmake.org/t/how-to-solve-following-multiple-uses-of-o-are-not-allowed-error/6220/3 "2022-09-14T22:53:24Z")

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Also note that the tasking compiler is not 100% supported by cmake yet.