These scripts

test/jdk/java/lang/invoke/VarHandles/generate-vh-tests.sh
test/jdk/java/nio/Buffer/genBasic.sh
test/jdk/java/nio/Buffer/genCopyDirectMemory.sh
test/jdk/java/nio/Buffer/genOrder.sh
test/jdk/java/util/Formatter/genBasic.sh

use the stream preprocessor build.tools.spp.Spp to generate tests from templates. Spp requires that its input and output be specified as

java build.tools.spp.Spp -i$input -o$output

and not as

java build.tools.spp.Spp <$input >$output

which is to say *not* via stdin and stdout. Presumably Spp was changed without updating these scripts. The scripts now fail to generate the expected tests with a NullPointerException:

$ sh ./genBasic.sh
Exception in thread "main" java.lang.NullPointerException
at java.base/java.io.FileInputStream.<init>(FileInputStream.java:147)
at java.base/java.io.FileInputStream.<init>(FileInputStream.java:110)
at build.tools.spp.Spp.main(Spp.java:98)