02/02: pack: "fakechroot" engine always creates its store.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit c088aa2988ef82289c87ebfd6d07d8f1464dd8f0
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Tue Jul 28 12:28:39 2020 +0200

    pack: "fakechroot" engine always creates its store.
    
    Previously it would silently fail to create the /gnu/store symlink when
    the host has a read-only /gnu as is the case in these tests.
    
    * gnu/packages/aux-files/run-in-namespace.c (exec_with_loader): Unlink
    the ancestor of ORIGINAL_STORE under NEW_ROOT.  Check the return value
    of 'symlink' when creating NEW_STORE.
    * tests/guix-pack-relocatable.sh: Check the contents of the store as
    seen by the wrapped executable, with all three engines, and with both
    "/gnu" and "/gnu/store" erased.
---
 gnu/packages/aux-files/run-in-namespace.c | 15 ++++++++++++++-
 tests/guix-pack-relocatable.sh            | 27 +++++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/gnu/packages/aux-files/run-in-namespace.c 
b/gnu/packages/aux-files/run-in-namespace.c
index 7f7e5c6..436c0b6 100644
--- a/gnu/packages/aux-files/run-in-namespace.c
+++ b/gnu/packages/aux-files/run-in-namespace.c
@@ -441,10 +441,23 @@ exec_with_loader (const char *store, int argc, char 
*argv[])
   char *new_root = mkdtemp (strdup ("/tmp/guix-exec-XXXXXX"));
   mirror_directory ("/", new_root, make_symlink);
 
+  /* 'mirror_directory' created a symlink for the ancestor of ORIGINAL_STORE,
+     typically "/gnu".  Remove that entry so we can create NEW_STORE
+     below.  */
+  const char *slash = strchr (original_store + 1, '/');
+  const char *top = slash != NULL
+    ? strndupa (original_store, slash - original_store)
+    : original_store;
+  char *new_store_top = concat (new_root, top);
+  unlink (new_store_top);
+
+  /* Now create the store under NEW_ROOT.  */
   char *new_store = concat (new_root, original_store);
   char *new_store_parent = dirname (strdup (new_store));
   mkdir_p (new_store_parent);
-  symlink (store, new_store);
+  err = symlink (store, new_store);
+  if (err < 0)
+    assert_perror (errno);
 
 #ifdef GCONV_DIRECTORY
   /* Tell libc where to find its gconv modules.  This is necessary because
diff --git a/tests/guix-pack-relocatable.sh b/tests/guix-pack-relocatable.sh
index 1ba3889..b8d36a0 100644
--- a/tests/guix-pack-relocatable.sh
+++ b/tests/guix-pack-relocatable.sh
@@ -90,7 +90,7 @@ case "`uname -m`" in
        # Try '-RR' and PRoot.
        tarball="`guix pack -RR -S /Bin=bin sed`"
        tar tvf "$tarball" | grep /bin/proot
-       (cd "$test_directory"; tar xvf "$tarball")
+       (cd "$test_directory"; tar xf "$tarball")
        run_without_store GUIX_EXECUTION_ENGINE="proot" \
        "$test_directory/Bin/sed" --version > "$test_directory/output"
        grep 'GNU sed' "$test_directory/output"
@@ -101,6 +101,29 @@ case "`uname -m`" in
        grep 'GNU sed' "$test_directory/output"
 
        chmod -Rf +w "$test_directory"; rm -rf "$test_directory"/*
+
+       if unshare -r true
+       then
+           # Check whether the store contains everything it should.  Check
+           # once when erasing $STORE_PARENT ("/gnu") and once when erasing
+           # $NIX_STORE_DIR ("/gnu/store").
+           tarball="`guix pack -RR -S /bin=bin bash-minimal`"
+           (cd "$test_directory"; tar xf "$tarball")
+
+           STORE_PARENT="`dirname $NIX_STORE_DIR`"
+           export STORE_PARENT
+
+           for engine in userns proot fakechroot
+           do
+               for i in $(guix gc -R $(guix build bash-minimal | grep -v -e 
'-doc$'))
+               do
+                   unshare -mrf sh -c "mount -t tmpfs none \"$NIX_STORE_DIR\"; 
GUIX_EXECUTION_ENGINE=$engine $test_directory/bin/sh -c 'echo 
$NIX_STORE_DIR/*'" | grep $(basename $i)
+                   unshare -mrf sh -c "mount -t tmpfs none \"$STORE_PARENT\";  
GUIX_EXECUTION_ENGINE=$engine $test_directory/bin/sh -c 'echo 
$NIX_STORE_DIR/*'" | grep $(basename $i)
+               done
+           done
+
+           chmod -Rf +w "$test_directory"; rm -rf "$test_directory"/*
+       fi
        ;;
     *)
        echo "skipping PRoot and Fakechroot tests" >&2
@@ -109,7 +132,7 @@ esac
 
 # Ensure '-R' works with outputs other than "out".
 tarball="`guix pack -R -S /share=share groff:doc`"
-(cd "$test_directory"; tar xvf "$tarball")
+(cd "$test_directory"; tar xf "$tarball")
 test -d "$test_directory/share/doc/groff/html"
 
 # Ensure '-R' applies to propagated inputs.  Failing to do that, it would fail