From f2ad9b37d52da03de16e7b9548bf819d2dde49ae Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Thu, 22 Oct 2026 06:25:47 +0530
Subject: [PATCH 1/2] Do not use TEMP as a shell variable name

install_hlint and install_docspec set TEMP to a relative download directory
and leave it set after they return. TEMP is the Windows temporary directory
variable, so programs run later in the same shell would use that directory,
which the EXIT trap removes. Use HLINT_TMP_DIR and DOCSPEC_TMP_DIR instead.
---
 packcheck.sh | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/packcheck.sh b/packcheck.sh
index b0ef9a10..f58191c3 100755
--- a/packcheck.sh
+++ b/packcheck.sh
@@ -2152,15 +2152,15 @@ install_hlint() {
   VERSION=$HLINT_VERSION
 
   URL="$HLINT_URL_PREFIX/download/v$VERSION/hlint-$VERSION-x86_64-$OS$EXT"
-  TEMP=$(mktemp -d .$PACKAGE-XXXXXX)
+  HLINT_TMP_DIR=$(mktemp -d .$PACKAGE-XXXXXX)
 
   cleanup(){
-      rm -r $TEMP
+      rm -r $HLINT_TMP_DIR
   }
   trap cleanup EXIT
 
   echo $URL
-  retry_cmd curl --fail --progress-bar --location -o$TEMP/$PACKAGE$EXT $URL
+  retry_cmd curl --fail --progress-bar --location -o$HLINT_TMP_DIR/$PACKAGE$EXT $URL
   if test "$?" -ne 0
   then
     die "Failed to download $URL"
@@ -2173,14 +2173,14 @@ install_hlint() {
 
   mkdir -p ${LOCAL_BIN}
   if [ "$OS" = "windows" ]; then
-      7z x -y $TEMP/$PACKAGE$EXT -o${TEMP} hlint-$VERSION/hlint.exe > /dev/null
-      mv ${TEMP}/hlint-${VERSION}/hlint.exe ${LOCAL_BIN}
+      7z x -y $HLINT_TMP_DIR/$PACKAGE$EXT -o${HLINT_TMP_DIR} hlint-$VERSION/hlint.exe > /dev/null
+      mv ${HLINT_TMP_DIR}/hlint-${VERSION}/hlint.exe ${LOCAL_BIN}
   elif [ "$OS" = "osx" ]; then
-      tar -xzvf $TEMP/$PACKAGE$EXT -C${TEMP} --include '*/hlint'
-      mv ${TEMP}/hlint-${VERSION}/hlint ${LOCAL_BIN}
+      tar -xzvf $HLINT_TMP_DIR/$PACKAGE$EXT -C${HLINT_TMP_DIR} --include '*/hlint'
+      mv ${HLINT_TMP_DIR}/hlint-${VERSION}/hlint ${LOCAL_BIN}
   else
-      tar -xzvf $TEMP/$PACKAGE$EXT -C${TEMP} --wildcards '*/hlint'
-      mv ${TEMP}/hlint-${VERSION}/hlint ${LOCAL_BIN}
+      tar -xzvf $HLINT_TMP_DIR/$PACKAGE$EXT -C${HLINT_TMP_DIR} --wildcards '*/hlint'
+      mv ${HLINT_TMP_DIR}/hlint-${VERSION}/hlint ${LOCAL_BIN}
   fi
   chmod +x $HLINT_PATH
 }
@@ -2307,9 +2307,9 @@ install_docspec() {
       *) die "install_docspec: unknown or unsupported os";;
   esac
 
-  TEMP=$(mktemp -d docspec-XXXXXX)
+  DOCSPEC_TMP_DIR=$(mktemp -d docspec-XXXXXX)
   cleanup(){
-      rm -r $TEMP
+      rm -r $DOCSPEC_TMP_DIR
   }
   trap cleanup EXIT
 
@@ -2318,10 +2318,10 @@ install_docspec() {
   # directly instead of version.
   #URL="$DOCSPEC_URL_PREFIX/download/cabal-docspec-$DOCSPEC_VERSION/cabal-docspec-$DOCSPEC_VERSION-x86_64-$OS.xz"
   #echo "Downloading $URL ..."
-  retry_cmd curl --fail --progress-bar --location -o$TEMP/cabal-docspec.xz $DOCSPEC_URL
+  retry_cmd curl --fail --progress-bar --location -o$DOCSPEC_TMP_DIR/cabal-docspec.xz $DOCSPEC_URL
   if test "$?" -ne 0
   then
-    rm -f $TEMP/cabal-docspec.xz
+    rm -f $DOCSPEC_TMP_DIR/cabal-docspec.xz
     die "Failed to download $DOCSPEC_URL"
   fi
 
@@ -2330,8 +2330,8 @@ install_docspec() {
     die "$DOCSPEC_PATH already exists, not overwriting."
   else
     mkdir -p $(dirname ${DOCSPEC_PATH})
-    xz -d < $TEMP/cabal-docspec.xz > $DOCSPEC_PATH
-    rm -f $TEMP/cabal-docspec.xz
+    xz -d < $DOCSPEC_TMP_DIR/cabal-docspec.xz > $DOCSPEC_PATH
+    rm -f $DOCSPEC_TMP_DIR/cabal-docspec.xz
     chmod +x $DOCSPEC_PATH
   fi
 }

From d91731cf46c91b32fd64b307a5fce99ef99b6934 Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Thu, 22 Oct 2026 06:25:47 +0530
Subject: [PATCH 2/2] Allow TEMP and TMP on Windows

Without them GetTempPath falls back to the Windows directory, so programs
create temporary files in C:\Windows. Pass them through in the GitHub
workflow template.
---
 .github/workflows/packcheck.yml | 2 +-
 Changelog.md                    | 2 ++
 packcheck.sh                    | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/packcheck.yml b/.github/workflows/packcheck.yml
index cb1acc56..e074ee2d 100644
--- a/.github/workflows/packcheck.yml
+++ b/.github/workflows/packcheck.yml
@@ -427,7 +427,7 @@ jobs:
               #PATH_VAR="$PATH_VAR:/usr/local/.ghcup/bin"
               ;;
             CYGWIN*|MINGW*|MSYS*)
-              for var in APPDATA CABAL_DIR; do
+              for var in APPDATA CABAL_DIR TEMP TMP; do
                 val="${!var}"
                 [ -n "$val" ] && ARGS="$ARGS $var=\"$(cygpath -u "$val")\""
               done
diff --git a/Changelog.md b/Changelog.md
index 4b6dbd95..221953d9 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -6,6 +6,8 @@
 * Add `CABAL_INDEX_TTL` option - do not attempt cabal update until it is
   stale by this many hours, saves some build time.
 * Windows: Support installing ghc using ghcup.
+* Windows: Allow `TEMP` and `TMP` on the command line, so that programs
+  use the system temporary directory instead of the Windows directory.
 * Caching: New `BUILD_ONLY_DEPS` and `BUILD_POST_DEPS` flags to
     allow pausing/resuming builds for CI cache optimization.
 * Diagnostics: Enhanced machine info captures `df`, `mount`, and
diff --git a/packcheck.sh b/packcheck.sh
index f58191c3..144900f9 100755
--- a/packcheck.sh
+++ b/packcheck.sh
@@ -365,6 +365,8 @@ GHCRTS \
 ALLOW_WIN_ENVVARS="\
 WINVER \
 APPDATA \
+TEMP \
+TMP \
 NUMBER_OF_PROCESSORS \
 PROCESSOR_IDENTIFIER \
 "