'uint32_t' does not name a type at SystemVersion.h in Linux

[matsujirushi]

An error occurs when compiling ReButtonApp in a Linux environment.

Error messages:

/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.h:21:1: error: 'uint32_t' does not name a type
 uint32_t getMajorVersion();
 ^
/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.h:24:1: error: 'uint32_t' does not name a type
 uint32_t getMinorVersion();
 ^
/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.h:27:1: error: 'uint32_t' does not name a type
 uint32_t getPatchVersion();
 ^
/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.cpp:21:1: error: 'uint32_t' does not name a type
 uint32_t getMajorVersion()
 ^
/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.cpp:27:1: error: 'uint32_t' does not name a type
 uint32_t getMinorVersion()
 ^
/home/ubuntu/.arduino15/packages/SeeedJP/hardware/SeeedJP_ReButton/2.1/cores/arduino/system/SystemVersion.cpp:33:1: error: 'uint32_t' does not name a type
 uint32_t getPatchVersion()

Screen shot:

Environment:

• Ubuntu 20.04
• Arduino IDE 2.0.4
• SeeedJP ReButton by Seeed K.K. Version 2.1