Revert activation procedure, with tweaks

* Convert CONDA_SHLVL to an integer. If this variable is non-zero then deactivate the current environment before activating a new one.
* Conda's initialization scripts don't handle shebang lines longer than 127 bytes on Linux. I'm aware they handle it in conda itself, but the "bug" is such that you cannot use conda to reap the benefits of their workaround(s).
* This redefines the __conda_exe shell function so that conda is always executed by the base environment's Python interpreter via CONDA_PYTHON_EXE.

1 files changed, 17 insertions, 13 deletions

diff --git a/src/lib/core/conda.c b/src/lib/core/conda.c
index 0e0161d..48ed6c4 100644
--- a/src/lib/core/conda.c
+++ b/src/lib/core/conda.c
@@ -266,24 +266,28 @@ int conda_activate(const char *root, const char *env_name) {
         return -1;
     }
 
+    // Fully activate conda and record its effect on the runtime environment
+    char command[PATH_MAX * 3];
+    const char *conda_shlvl_str = getenv("CONDA_SHLVL");
+    unsigned long conda_shlvl = 0;
+    if (conda_shlvl_str) {
+        conda_shlvl = strtol(conda_shlvl_str, NULL, 10);
+    }
+
     if (conda_prepend_bin(root)) {
         remove(logfile);
         return -1;
     }
 
-    // Fully activate conda and record its effect on the runtime environment
-    char command[PATH_MAX * 3];
-    const char *conda_shlvl = getenv("CONDA_SHLVL");
-    if (conda_shlvl == NULL || strcmp(conda_shlvl, "0") == 0) {
-        // First-run initialization
-        snprintf(command, sizeof(command) - 1, "source %s; source %s; conda activate %s &>/dev/null; env -0", path_conda, path_mamba, env_name);
-    } else {
-        // Conda is already available and configured.
-        // Make calls directly to conda using conda's base interpreter.
-        // The shell functions generated by sourcing path_conda and path_mamba are extremely inconsistent
-        // in this environment. DO NOT USE THEM.
-        snprintf(command, sizeof(command) - 1, "$CONDA_PYTHON_EXE $CONDA_EXE activate %s &>/dev/null; env -0", env_name);
-    }
+    snprintf(command, sizeof(command) - 1,
+        "set -a\n"
+        "source %s\n"
+        "function __conda_exe (\n\t\"$CONDA_PYTHON_EXE\" \"$CONDA_EXE\" $_CE_M $_CE_CONDA \"$@\"\n)\n"
+        "source %s\n"
+        "%s\n"
+        "conda activate %s 1>&2\n"
+        "env -0\n", path_conda, path_mamba, conda_shlvl ? "conda deactivate" : ":", env_name);
+
     int retval = shell(&proc, command);
     if (retval) {
         // it didn't work; drop out for cleanup