diff --git a/fuse_sideload.c b/fuse_sideload.c
index 4e11e01..1dd84e9 100644
--- a/fuse_sideload.c
+++ b/fuse_sideload.c
@@ -106,12 +106,12 @@
 
     vec[0].iov_base = &hdr;
     vec[0].iov_len = sizeof(hdr);
-    vec[1].iov_base = data;
+    vec[1].iov_base = /* const_cast */(void*)(data);
     vec[1].iov_len = len;
 
     res = writev(fd->ffd, vec, 2);
     if (res < 0) {
-        printf("*** REPLY FAILED *** %d\n", errno);
+        printf("*** REPLY FAILED *** %s\n", strerror(errno));
     }
 }
 
@@ -430,7 +430,7 @@
 
     char opts[256];
     snprintf(opts, sizeof(opts),
-             ("fd=%d,user_id=%d,group_id=%d,max_read=%zu,"
+             ("fd=%d,user_id=%d,group_id=%d,max_read=%u,"
               "allow_other,rootmode=040000"),
              fd.ffd, fd.uid, fd.gid, block_size);
 
diff --git a/mtdutils/mtdutils.c b/mtdutils/mtdutils.c
index d04b26e..9a17e38 100644
--- a/mtdutils/mtdutils.c
+++ b/mtdutils/mtdutils.c
@@ -313,8 +313,8 @@
             memcpy(&before, &after, sizeof(struct mtd_ecc_stats));
         } else if ((mgbb = ioctl(fd, MEMGETBADBLOCK, &pos))) {
             fprintf(stderr,
-                    "mtd: MEMGETBADBLOCK returned %d at 0x%08llx (errno=%d)\n",
-                    mgbb, pos, errno);
+                    "mtd: MEMGETBADBLOCK returned %d at 0x%08llx: %s\n",
+                    mgbb, pos, strerror(errno));
         } else {
             return 0;  // Success!
         }
@@ -419,8 +419,8 @@
         if (ret != 0 && !(ret == -1 && errno == EOPNOTSUPP)) {
             add_bad_block_offset(ctx, pos);
             fprintf(stderr,
-                    "mtd: not writing bad block at 0x%08lx (ret %d errno %d)\n",
-                    pos, ret, errno);
+                    "mtd: not writing bad block at 0x%08lx (ret %d): %s\n",
+                    pos, ret, strerror(errno));
             pos += partition->erase_size;
             continue;  // Don't try to erase known factory-bad blocks.
         }
diff --git a/updater/blockimg.c b/updater/blockimg.c
index 9c39634..90b55b2 100644
--- a/updater/blockimg.c
+++ b/updater/blockimg.c
@@ -464,7 +464,7 @@
 
     if (directory == NULL) {
         if (errno != ENOENT) {
-            fprintf(stderr, "failed to opendir %s (errno %d)\n", dirname, errno);
+            fprintf(stderr, "opendir \"%s\" failed: %s\n", dirname, strerror(errno));
         }
         return;
     }
@@ -495,7 +495,7 @@
     }
 
     if (closedir(directory) == -1) {
-        fprintf(stderr, "failed to closedir %s (errno %d)\n", dirname, errno);
+        fprintf(stderr, "closedir \"%s\" failed: %s\n", dirname, strerror(errno));
     }
 }
 
@@ -508,7 +508,7 @@
     }
 
     if (stat(fn, &st) == -1) {
-        fprintf(stderr, "failed to stat %s (errno %d)\n", fn, errno);
+        fprintf(stderr, "stat \"%s\" failed: %s\n", fn, strerror(errno));
         return;
     }
 
@@ -524,7 +524,7 @@
         fprintf(stderr, "deleting %s\n", fn);
 
         if (unlink(fn) == -1 && errno != ENOENT) {
-            fprintf(stderr, "failed to unlink %s (errno %d)\n", fn, errno);
+            fprintf(stderr, "unlink \"%s\" failed: %s\n", fn, strerror(errno));
         }
     }
 }
@@ -553,7 +553,7 @@
 
     if (rmdir(dirname) == -1) {
         if (errno != ENOENT && errno != ENOTDIR) {
-            fprintf(stderr, "failed to rmdir %s (errno %d)\n", dirname, errno);
+            fprintf(stderr, "rmdir \"%s\" failed: %s\n", dirname, strerror(errno));
         }
     }
 
@@ -587,7 +587,7 @@
 
     if (res == -1) {
         if (errno != ENOENT || printnoent) {
-            fprintf(stderr, "failed to stat %s (errno %d)\n", fn, errno);
+            fprintf(stderr, "stat \"%s\" failed: %s\n", fn, strerror(errno));
         }
         goto lsout;
     }
@@ -602,7 +602,7 @@
     fd = TEMP_FAILURE_RETRY(open(fn, O_RDONLY));
 
     if (fd == -1) {
-        fprintf(stderr, "failed to open %s (errno %d)\n", fn, errno);
+        fprintf(stderr, "open \"%s\" failed: %s\n", fn, strerror(errno));
         goto lsout;
     }
 
@@ -663,7 +663,7 @@
     fd = TEMP_FAILURE_RETRY(open(fn, O_WRONLY | O_CREAT | O_TRUNC | O_SYNC, STASH_FILE_MODE));
 
     if (fd == -1) {
-        fprintf(stderr, "failed to create %s (errno %d)\n", fn, errno);
+        fprintf(stderr, "failed to create \"%s\": %s\n", fn, strerror(errno));
         goto wsout;
     }
 
@@ -672,12 +672,12 @@
     }
 
     if (fsync(fd) == -1) {
-        fprintf(stderr, "failed to fsync %s (errno %d)\n", fn, errno);
+        fprintf(stderr, "fsync \"%s\" failed: %s\n", fn, strerror(errno));
         goto wsout;
     }
 
     if (rename(fn, cn) == -1) {
-        fprintf(stderr, "failed to rename %s to %s (errno %d)\n", fn, cn, errno);
+        fprintf(stderr, "rename(\"%s\", \"%s\") failed: %s\n", fn, cn, strerror(errno));
         goto wsout;
     }
 
@@ -737,14 +737,14 @@
     res = stat(dirname, &st);
 
     if (res == -1 && errno != ENOENT) {
-        ErrorAbort(state, "failed to stat %s (errno %d)\n", dirname, errno);
+        ErrorAbort(state, "stat \"%s\" failed: %s\n", dirname, strerror(errno));
         goto csout;
     } else if (res != 0) {
         fprintf(stderr, "creating stash %s\n", dirname);
         res = mkdir(dirname, STASH_DIRECTORY_MODE);
 
         if (res != 0) {
-            ErrorAbort(state, "failed to create %s (errno %d)\n", dirname, errno);
+            ErrorAbort(state, "mkdir \"%s\" failed: %s\n", dirname, strerror(errno));
             goto csout;
         }
 
@@ -1408,7 +1408,7 @@
     }
 
     if (fstat(params->fd, &st) == -1) {
-        fprintf(stderr, "failed to fstat device to erase (errno %d)\n", errno);
+        fprintf(stderr, "failed to fstat device to erase: %s\n", strerror(errno));
         goto pceout;
     }
 
@@ -1437,7 +1437,7 @@
             blocks[1] = (tgt->pos[i * 2 + 1] - tgt->pos[i * 2]) * (uint64_t) BLOCKSIZE;
 
             if (ioctl(params->fd, BLKDISCARD, &blocks) == -1) {
-                fprintf(stderr, "failed to blkdiscard (errno %d)\n", errno);
+                fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
                 // Continue anyway, nothing we can do
             }
         }
@@ -1574,7 +1574,7 @@
     params.fd = TEMP_FAILURE_RETRY(open(blockdev_filename->data, O_RDWR));
 
     if (params.fd == -1) {
-        fprintf(stderr, "failed to open %s: %s", blockdev_filename->data, strerror(errno));
+        fprintf(stderr, "open \"%s\" failed: %s\n", blockdev_filename->data, strerror(errno));
         goto pbiudone;
     }
 
@@ -1587,8 +1587,9 @@
         pthread_attr_init(&attr);
         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 
-        if (pthread_create(&params.thread, &attr, unzip_new_data, &params.nti) != 0) {
-            fprintf(stderr, "failed to create a thread (errno %d)\n", errno);
+        int error = pthread_create(&params.thread, &attr, unzip_new_data, &params.nti);
+        if (error != 0) {
+            fprintf(stderr, "pthread_create failed: %s\n", strerror(error));
             goto pbiudone;
         }
     }
@@ -1719,7 +1720,7 @@
 pbiudone:
     if (params.fd != -1) {
         if (fsync(params.fd) == -1) {
-            fprintf(stderr, "failed to fsync device (errno %d)\n", errno);
+            fprintf(stderr, "fsync failed: %s\n", strerror(errno));
         }
         TEMP_FAILURE_RETRY(close(params.fd));
     }
@@ -1875,7 +1876,7 @@
 
     int fd = open(blockdev_filename->data, O_RDWR);
     if (fd < 0) {
-        ErrorAbort(state, "failed to open %s: %s", blockdev_filename->data, strerror(errno));
+        ErrorAbort(state, "open \"%s\" failed: %s", blockdev_filename->data, strerror(errno));
         goto done;
     }