I have warning: Warning: 'sleep_for' is deprecated: Pass a chrono duration, not an integer millisecond count. For example use 5srather than5000. [since mbed-os-6.0.0] [-Wdeprecated-declarations] in "main.cpp",
If I use Online Compiler :
ThisTread:sleep_for(5s);
it build with out warning.
but offline build GCC_ARM trow an error that it does not recognize ‘s’.
I don’t know how about other revisions but with the gcc-arm-none-eabi-9-2019-q4-major the chrono literals like 5s work fine. And I expect it should be the same with newer revisions. Maybe you just left a space char between the number and the ‘s’ char, like 5 s. Since I use a code beautifier (which is not aware of those special literals) I also frequently have to fix such errors manually.