diff --git a/README b/README
index 141d8aa672f3f46e6d975ce3653436009b4c3b04..2dedb39d191c869a3e0ed4220cebacb9eb38a543 100644
--- a/README
+++ b/README
@@ -46,8 +46,8 @@ AUTHOR
 
 VERSION
 
-    0.6.7
+    0.6.8
 
 LAST UPDATED
 
-    Tuesday, April 16th, 2019
+    Tuesday, April 30th, 2019
diff --git a/definition-files/comet/pytorch/pytorch-gpu.def b/definition-files/comet/pytorch/pytorch-gpu.def
index e469c6932d6e5464f8927b720ec254f14ae44c0a..a5fe8fcc5f3e13390a29a1ae88e577e40095b825 100644
--- a/definition-files/comet/pytorch/pytorch-gpu.def
+++ b/definition-files/comet/pytorch/pytorch-gpu.def
@@ -9,7 +9,7 @@ OSVersion: xenial
     APPLICATION_URL http://pytorch.org/
 
     SYSTEM_NAME comet
-    SYSTEM_SINGULARITY_VERSION 2.5.2
+    SYSTEM_SINGULARITY_VERSION 2.6.1
     SYSTEM_URL http://www.sdsc.edu/support/user_guides/comet.html
 
     SINGULARITY_IMAGE_SIZE 32768
@@ -17,7 +17,7 @@ OSVersion: xenial
     AUTHOR_NAME Marty Kandes
     AUTHOR_EMAIL mkandes@sdsc.edu
 
-    LAST_UPDATED 20190110
+    LAST_UPDATED 20190227
 
 %setup
 
@@ -349,7 +349,7 @@ OSVersion: xenial
     # Download, build, and install PyTorch for python2
     export CC='mpicc'
     export CXX='mpicxx'
-    export CFLAGS='-march=haswell -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16 -msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4 -mno-xop -mbmi -mbmi2 -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mrdrnd -mf16c -mfsgsbase -mno-rdseed -mno-prfchw -mno-adx -mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mtune=haswell'
+    export CFLAGS='-std=gnu -O3 -ffast-math -march=haswell -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16 -msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4 -mno-xop -mbmi -mbmi2 -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mrdrnd -mf16c -mfsgsbase -mno-rdseed -mno-prfchw -mno-adx -mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mtune=haswell'
     export USE_OPENMP=1
     export USE_NNPACK=1
     export USE_QNNPACK=1
@@ -363,7 +363,7 @@ OSVersion: xenial
     export USE_CUDNN=1
     export USE_NCCL=1
     export USE_OPENCV=1
-    export TORCH_CUDA_ARCH_LIST="3.7;6.0"
+    export TORCH_CUDA_ARCH_LIST="3.7;6.0;7.0"
     git clone --recursive https://github.com/pytorch/pytorch
     cd /opt/pytorch
     git checkout v1.0.0
diff --git a/naked-singularity.sh b/naked-singularity.sh
index e7d1fb312b9fab46595bd0e28ba889f3abda3c26..ff238729352d66e4b8f3ee1be8d1e6c695ec05ff 100755
--- a/naked-singularity.sh
+++ b/naked-singularity.sh
@@ -28,7 +28,7 @@
 #
 # LAST UPDATED
 #
-#     Tuesday, November 6th, 2018
+#     Tuesday, April 30th, 2019
 #
 # ----------------------------------------------------------------------
 
@@ -297,6 +297,10 @@ naked_install() {
     sudo yum groupinstall -y 'Development Tools'
     echo 'sudo yum install -y libarchive-devel'
     sudo yum install -y libarchive-devel
+    echo 'sudo yum install -y epel-release'
+    sudo yum install -y epel-release
+    echo 'sudo yum install -y debootstrap'
+    sudo yum install -y debootstrap
 
   elif [[ "${operating_system}" = 'ubuntu' ]]; then