autotools.bbclass: Fix m4 file race

If something removes .m4 files from the aclocal directory whilst aclocal is
running it gets upset. To avoid this we need to take a copy of the aclocal
directory and build against this instead.

[YOCTO #861]

(From OE-Core rev: 6a4778e21341f031569f561e7699d2c616b60af0)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/meta/classes/autotools.bbclass b/meta/classes/autotools.bbclass
index e5c13ae691..8f65b709fd 100644
--- a/meta/classes/autotools.bbclass
+++ b/meta/classes/autotools.bbclass
@@ -111,8 +111,13 @@ autotools_do_configure() {
                         if [ -d ${STAGING_DATADIR_NATIVE}/aclocal-$AUTOV ]; then
                                 acpaths="$acpaths -I${STAGING_DATADIR_NATIVE}/aclocal-$AUTOV"
                         fi
+                        # The aclocal directory could get modified by other processes 
+                        # uninstalling data from the sysroot. See Yocto #861 for details.
+                        # We avoid this by taking a copy here and then files cannot disappear.
                         if [ -d ${STAGING_DATADIR}/aclocal ]; then
-                                acpaths="$acpaths -I ${STAGING_DATADIR}/aclocal"
+                                mkdir -p ${B}/aclocal-copy/
+                                cp ${STAGING_DATADIR}/aclocal/* ${B}/aclocal-copy/
+                                acpaths="$acpaths -I ${B}/aclocal-copy/"
                         fi
                         # autoreconf is too shy to overwrite aclocal.m4 if it doesn't look
                         # like it was auto-generated.  Work around this by blowing it away