try building libgpgme and libgpg-error

install_dependencies.linux.sh

@@ -1,3 +1,28 @@
 #!/bin/bash
 sudo apt-get update
-sudo apt-get install -y libffi-dev gnupg2 pgpdump libgpgme11-dev
+sudo apt-get install -y libffi-dev gnupg2
+
+if [ -z "${TOXENV}" ]; then
+    sudo apt-get install gpgsm libassuan-dev libgpg-error-dev swig
+
+    # build/install gpgme 1.8.0 manually
+    wget https://www.gnupg.org/ftp/gcrypt/gpgme/gpgme-1.7.0.tar.bz2
+    tar -xvf gpgme-1.7.0.tar.bz2
+    pushd gpgme-1.7.0
+    ./configure \
+        --prefix=/usr \
+        --disable-fd-passing \
+        --disable-static \
+        --disable-gpgsm-test \
+        --infodir=/usr/share/info \
+        --with-gpg=/usr/bin/gpg \
+        --with-gpgsm=/usr/bin/gpgsm \
+        --with-gpgconf=/usr/bin/gpgconf
+    make
+    sudo make install
+    sudo ldconfig
+    popd
+
+    gpgconf --kill gpg-agent
+    gpg-agent --daemon --homedir tests/gnupghome
+fi