Ubuntu jdk9 build error

[Semyon Sadetsky]

Hi,

Could somebody advise what can be the reason for the next build error:

Compiling 161 files for BUILD_TOOLS_JDK
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
GensrcMisc.gmk:63: *** You have to specify LANG for native compilation 
BUILD_GENSRC_SOR_EXE.  Stop.
make[2]: *** [java.base-gensrc-jdk] Error 1
make[1]: *** [main] Error 1
make: *** [default] Error 2

setting LANG to C affects nothing.

Thank you.
--Semyon Sadetsky