diff --git a/pkgs/build-support/setup-hooks/make-symlinks-relative.sh b/pkgs/build-support/setup-hooks/make-symlinks-relative.sh
index cd9c2eaa2d80..f34353a7617b 100644
--- a/pkgs/build-support/setup-hooks/make-symlinks-relative.sh
+++ b/pkgs/build-support/setup-hooks/make-symlinks-relative.sh
@@ -6,8 +6,8 @@ postFixupHooks+=(_makeSymlinksRelative)
 _makeSymlinksRelative() {
     local symlinkTarget
 
-    if [ -n "${dontRewriteSymlinks-}" ]; then
-        return 0
+    if [ "${dontRewriteSymlinks-}" ] || [ ! -e "$prefix" ]; then
+       return
     fi
 
     while IFS= read -r -d $'\0' f; do
diff --git a/pkgs/build-support/setup-hooks/strip.sh b/pkgs/build-support/setup-hooks/strip.sh
index 104b5515b3db..f5e3bdced699 100644
--- a/pkgs/build-support/setup-hooks/strip.sh
+++ b/pkgs/build-support/setup-hooks/strip.sh
@@ -36,7 +36,7 @@ _doStrip() {
         local -n ranlibCmd="${ranlibCmds[$i]}"
 
         # `dontStrip` disables them all
-        if [[ "${dontStrip-}" || "${flag-}" ]] || ! type -f "${stripCmd-}" 2>/dev/null
+        if [[ "${dontStrip-}" || "${flag-}" ]] || ! type -f "${stripCmd-}" 2>/dev/null 1>&2
         then continue; fi
 
         stripDirs "$stripCmd" "$ranlibCmd" "$debugDirList" "${stripDebugFlags[*]:--S}"
diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index b07420bb4185..d37fc029cfed 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -1253,7 +1253,7 @@ buildPhase() {
     runHook preBuild
 
     if [[ -z "${makeFlags-}" && -z "${makefile:-}" && ! ( -e Makefile || -e makefile || -e GNUmakefile ) ]]; then
-        echo "no Makefile, doing nothing"
+        echo "no Makefile or custom buildPhase, doing nothing"
     else
         foundMakefile=1
 
@@ -1323,6 +1323,15 @@ checkPhase() {
 installPhase() {
     runHook preInstall
 
+    # Dont reuse 'foundMakefile' set in buildPhase, a makefile may have been created in buildPhase
+    if [[ -z "${makeFlags-}" && -z "${makefile:-}" && ! ( -e Makefile || -e makefile || -e GNUmakefile ) ]]; then
+        echo "no Makefile or custom installPhase, doing nothing"
+        runHook postInstall
+        return
+    else
+        foundMakefile=1
+    fi
+
     if [ -n "$prefix" ]; then
         mkdir -p "$prefix"
     fi