Ported WSL2 fix from HeartGold

platform.mk

@@ -1,38 +1,46 @@
 
 WSLENV ?= no
 ifeq ($(WSLENV),no)
-NOWINE = 0
+  NOWINE = 0
 else
-NOWINE = 1
+  # As of build 17063, WSLENV is defined in both WSL1 and WSL2
+  # so we need to use the kernel release to detect between
+  # the two.
+  UNAME_R := $(shell uname -r)
+  ifeq ($(findstring WSL2,$(UNAME_R)),)
+    NOWINE = 1
+  else
+    NOWINE = 0
+  endif
 endif
 
 ifeq ($(OS),Windows_NT)
-EXE := .exe
-WINE :=
-GREP := grep -P
-SED := sed -r
-SHA1SUM := sha1sum
-MKTEMP := mktemp
+  EXE := .exe
+  WINE :=
+  GREP := grep -P
+  SED := sed -r
+  SHA1SUM := sha1sum
+  MKTEMP := mktemp
 else
-EXE :=
-WINE := wine
-UNAME_S := $(shell uname -s)
-ifeq ($(UNAME_S),Darwin)
-GREP := grep -E
-SED := gsed -r
-SHA1SUM := shasum
-MKTEMP := gmktemp
-else
-GREP := grep -P
-SED := sed -r
-SHA1SUM := sha1sum
-MKTEMP := mktemp
-endif
+  EXE :=
+  WINE := wine
+  UNAME_S := $(shell uname -s)
+  ifeq ($(UNAME_S),Darwin)
+    GREP := grep -E
+    SED := gsed -r
+    SHA1SUM := shasum
+    MKTEMP := gmktemp
+  else
+    GREP := grep -P
+    SED := sed -r
+    SHA1SUM := sha1sum
+    MKTEMP := mktemp
+  endif
 endif
 
 ifeq ($(NOWINE),1)
-WINE :=
-WINPATH := wslpath
+  WINE :=
+  WINPATH := wslpath
 else
-WINPATH := winepath
+  WINPATH := winepath
 endif